perso.imt-mines-albi.frjourneau/rapports/rt/rt aude mic… · web viewaerosols international...

TECHNICAL REPORT

Aude MICHON May-July 2004 IFI 2006

Analysis of discrepancies concerning Analysis of discrepancies concerning production data, development of a production data, development of a

maintenance management system and study of maintenance management system and study of a water plant design in a company specialized a water plant design in a company specialized

in toiletries in toiletries

TECHNICAL REPORT

Swallowfield House Person in charge of the trainee:Station Road Mr Keri ALLCHURCHTAZI 8 NL WellingtonENGLAND

Aude MICHON May-July 2004 IFI 2006

- I -

Analysis of discrepancies concerning Analysis of discrepancies concerning production data, development of a production data, development of a

maintenance management system and study of maintenance management system and study of a water plant design in a company specialized a water plant design in a company specialized

in toiletries in toiletries

TECHNICAL REPORT Swallowfield

Aude Michon

SUMMARYSUMMARY____________

In the Swallowfield Company, which is specialized in aerosols products, two computer systems are used to record and manage the production data. Several discrepancies had been found between them. They are mainly due to supervisors calculation mistakes. To reduce the number of mistakes, one solution is to use the report of one computer system (Probase) to record the information in the other one (Fourth Shift).

Another computer system is used for the maintenance management. A new clearer weekly work schedule has been designed from this software. This new schedule is now used by the technicians for them to know the work they have to do. Options have also been developed in order to do some preventive maintenance.

This year, one important project of this company is about a new water treatment plant. After calculations, we can say that the actual 2 inch pipework can supply this new plant.

Water is needed to manufacture the products but also to cool the manufacturing tanks. Cooling by mains water is quite expensive. A way to reduce this cost would be to cool rooms 1 and 2 by cooling tower water. To check if this idea is feasible, the cooling load will have to be calculated.

- II -


Aude Michon

FOREWORDSFOREWORDS

________________

I would like to say particularly thank you to my company tutor M. K. Allchurch for his warm welcome, his patience and his good mood. I also would like to say a big thank you to Audrey, for her kindness, her spontaneity, her pancakes and chocolate bars…

Thank you to Pauline and Caroline. I really appreciated their help for my accommodation researches and for the opening of a bank account in England.

- III -


Aude Michon

CONTENTSCONTENTS__________

SUMMARY................................................................................................................................IIFOREWORDS........................................................................................................................IIIINTRODUCTION.....................................................................................................................1

I.I. SWALLOWFIELD, A COMPANY SPECIALIZED IN AEROSOLS PRODUCTSSWALLOWFIELD, A COMPANY SPECIALIZED IN AEROSOLS PRODUCTS2

A. A company which stresses on innovation.......................................................................2B. General process: from the manufacturing rooms to the finished product.......................3

II.II. INVESTIGATE WHY PRODUCTION FIGURES AS SHOWN IN TWO INVESTIGATE WHY PRODUCTION FIGURES AS SHOWN IN TWO COMPUTER SYSTEMS DIFFER INSTEAD OF BEING THE SAMECOMPUTER SYSTEMS DIFFER INSTEAD OF BEING THE SAME............................5

A. Calculation of the labour rate used in Probase and the one used in Fourth Shift...........81) a £11.00 labour rate used by Probase........................................................................82) a £11.00 labour rate used by Fourth Shift..................................................................8

B. Comparison between the Operator hours as shown in PB, those as shown in 4S and the real ones..................................................................................................................................9

1) First step: compare the figures recorded in Probase to those written on the supervisor sheets...............................................................................................................102) Second step: compare the figures written on the supervisor sheets to those written on the end of order sheets.................................................................................................133) Suggestions to reduce the number of mistakes.........................................................18

C. Comparison between the costing recorded in PB and those recorded in 4S.................22D. A way to reduce the number of mistakes: using a Probase report to record the production figures into Fourth Shift.....................................................................................25

III.III. INVESTIGATE HOW TO DEVELOP THE USE OF THE MAINTENANCE INVESTIGATE HOW TO DEVELOP THE USE OF THE MAINTENANCE MANAGEMENT SYSTEMMANAGEMENT SYSTEM...................................................................................................26

A. Design a new weekly work schedule report.................................................................26B. Investigation about the Resource planning use possibility...........................................27C. Develop Fault Codes to be able to do some Preventive Maintenance..........................27

IV.IV. RAW WATER SUPPLY DESIGN STUDYRAW WATER SUPPLY DESIGN STUDY.............................................................29A. The engineering department.........................................................................................29B. Check if the actual pipework can supply the new water plant system..........................29

1. Features of the 2 inch pipework (52 mm)...............................................................302. Features of the 3 inch pipework (80 mm).............................................................33

V.V. COOLING ROOMS 1 AND 2 BY COOLING TOWER WATER: A CHEAPER COOLING ROOMS 1 AND 2 BY COOLING TOWER WATER: A CHEAPER SOLUTION?SOLUTION?...........................................................................................................................37

CONCLUSION........................................................................................................................39BIBLIOGRAPHIE......................................................................................................................iADDITIONAL DOCUMENTS................................................................................................ii

- IV -

TECHNICAL REPORT SwallowfieldAude Michon

INTRODUCTIONINTRODUCTION____________

Swallowfield plc is the holding company of Aerosols International Limited and Cosmetics Plus Limited. Aerosols International Limited produces essentially aerosols products such as antiperspirants and hair sprays for example, but also some other kind of products such as roll-ons or body cream.

This company produces about 5 millions of toiletries or home cares every month. Eleven different lines are used to produce such a quantity. To control all the figures concerning the production, two computer systems are involved. The issue is that the labour variances (difference between the labours costs expected and the real one) calculated by each system are different instead of being the same. So mistakes concerning these labour variances have to be found in order to try to improve the actual system and to be able to rely on these computer systems.

Another computer system is used for the maintenance management. But it is not fully exploited yet. Creating a new weekly schedule and investigate the use of some options about the preventive maintenance can help to optimise this software use.

Now if we think about the future, a new important project is studying in this company. It is about a new water treatment plant. Actually pure water is needed to manufacture the products and customers become more and more particular about it. To be able to achieve this project, one thing to know is if the actual pipework could supply the new plant.

Water is also needed to cool the products when they are being mixed. Until now, tanks from room 1 and 2 have been cooled by mains water. To reduce the water consumption cost, an idea would be to use the cooling tower water instead of the mains water. Some calculations have to be made to check if it is feasible.

- 1 -


I.I. SWALLOWFIELD, A COMPANY SPECIALIZED IN AEROSOLS SWALLOWFIELD, A COMPANY SPECIALIZED IN AEROSOLS PRODUCTSPRODUCTS

A. A company which stresses on innovation

Aerosols International Limited is one of the two companies which belong to the Swallowfield group. Aerosols International Limited has been created in 1950 and is located in Wellington in Somerset. This company is specialized in aerosols production.

The other company which belongs to the Swallowfield group is called Cosmetics Plus Limited. It’s located in Bideford (in Devon), not far from Aerosols International Limited. Cosmetics Plus Limited is specialized in Cosmetics production, as it’s indicated by its name.

Aerosols International Limited introduced the first commercial aerosol into the UK in 1950 and since then, they have not kept investing in new products and new technologies. In 1968 it was the first factory which installed bulk hydrocarbon propellant tanks in the UK. Innovating is their key word. Here are some examples of their progress:

1992: they introduced innovating solutions for compressed air propelled products.

1998: they produced the first post foaming shower gel using Bag-on-Valve technology

1999: developed crackling body spray technology 2001: developed their first food product: a butter oil spray 2002: invested in 'computer controlled' state of the art mixing equipment1

Most of the products they made are toiletries like shower gels, antiperspirants and after shave gels. But they also produce home care as we can see below:

Toiletries Home care

hairstyling haircare shaving mens grooming bodycare facial skincare fragrance depilatories

personal wash

home fragrance air fresheners surface cleaners triggers laundry aids

stain remove

Table 1 : products offered by this factory2

1 Site www.swallofield.com 2 Site www.swallofield.com

- 2 -

http://www.swallofield.com/

http://www.swallofield.com/


They also make some gift packs for some specials day as Christmas, or the father’s day.

Most of their products are packaged in aerosols but they also can make other product formats as roll-ons, glass bottles for perfumes, sticks, pumps, trigger packs…So they can offer a wide choice of toiletries and home cares.

Aerosols International Limited employs now about 380 people. It’s a contract manufacturer so it makes products for other companies. It works for some big companies like Next, Boots, Hema, RB but also for some supermarkets like Sainsbury or Tesco. All their products bear the brand of their customers. In August 2004, this company changed its name. It is now called Swallowfield instead of Aerosols International.

B. General process: from the manufacturing rooms to the finished product

Most of their products are packaged in aerosols. It’s their field. They buy all the components needed (cans, valves, caps, actuators) and also the raw materials (chemical products…). But they manufacture themselves the different products. This process takes place in seven rooms. In each one, several tanks are used to mix and heat or cool the product.

To check if the manufactured product is right, some people who work in the Quality Control laboratory test it at the end of the process. The different tests depend of the product. They can check for example the colour and the odour with a standard. For some products as body lotion, they also check the viscosity, and the pH. But this list is not exhaustive.

A new microbiological laboratory has just been built. It is for all the water based products (body cream…). Customers are more and more particular about the water quality used in the products. It is harder and harder to respect their requirements. But to stay competitive, companies have to make efforts to satisfy them, even if their requirements are not always logical. That is why this laboratory has been built.

If the product is not right, some ingredients can be added to the mixture to modify it. Once it has been checked and found right, the product can be used on the line. The lines differ according to the product which is going to be filled. But we can find some similar steps on each line:

Put valves on the cans Crimp valves on the cans Fill the can with the product Fill the can with the gas Weight the full cans Lay the cans under water at about 55°C Put the actuators Put the caps Package

The bath is needed to be sure that there are no leaks (if there are leaks you can see some bubbles in the water). Moreover the water is between 50 and 60°C in order to check if the aerosols do not have any problem at such a high temperature.

- 3 -


The following figure shows an example of a production line. The necessary steps and the average number of required operators are indicated.

The number of operators varies according to the product which is making. Most of the lines work with about 8 operators.

- 4 -

Cans

BATH(from 50 to 60°C)

Capper

Packaging

Valves

Check weigher

ConcentrateFiller

Actuators

Supervisor

Conveyor

Operator

Figure 1 : production line example


Supervisors have to check if people work properly and if there is no problem on the line (for example trouble on a machine). They check the components every hour to be sure they use the right ones. They also examine the aerosols at the end of the line to check if cans has not been damaged by a machine and if the right code is printed under it. They also have to fill some sheets about their checks but also their output.

A white board is hanged near each line. Supervisors have to fill this board, by indicating what they should produce, what they have really produced, the units per operator per hour and the efficiency. They also write on it the time of breaks and if they have had some trouble with a machine or anything else. They fill this board at each end of shift.

Figures written by the supervisors are recorded in 2 systems to have some archives and to compare the production figures to those which were expected. But there is an issue because figures recorded in these two computer systems differ instead of being the same.

II.II. INVESTIGATE WHY PRODUCTION FIGURES AS SHOWN IN TWO INVESTIGATE WHY PRODUCTION FIGURES AS SHOWN IN TWO COMPUTER SYSTEMS DIFFER INSTEAD OF BEING THE SAMECOMPUTER SYSTEMS DIFFER INSTEAD OF BEING THE SAME

Two computer systems are used in the factory to record all the figures which are necessary to make the factory works. One of them is called Fourth Shift (4S) and the other one is called Probase (PB).

Fourth Shift is a network system. It can be used by people working in most of the departments. For example it is used by the stores to record the stock variances. It is also used by the production department to record all the figures concerning the line work. Those are just examples. The costing of the production is also recorded in it.

Probase is more limited. It is used by the production department and produces a daily production report3. On this daily production report some details about the production can be read. It is put in line number order. So you can see for example for each day the quantity filled, the time taken and the efficiency for any order number and any line.

It also produces an “Orders by period” document4 which also gives details about the production. But on this sheet, the information is put in line number order for a whole period.

In this company, all the figures are indicated by period and not by month. A period includes 4 weeks. So there are 13 period in a year. For example a new financial year began on the 28th of June 2004 to finish in summer 2005.

The daily production report and the “orders by period” sheet are two different kinds of documents which aim to report all the figures interesting to know about the production.

The labour costs expected are recorded both in Probase and Fourth Shift. The real ones are also calculated both in Probase and Fourth Shift. So these two computer systems can give

3 example of daily production report on Additional document I4 example of “Orders by period” sheet on Additional document XII

- 5 -


the labour variance which is the difference between the labour costs expected and the real ones. But the problem is that although they should be the same, the labour variances as shown in Probase and those as shown in Fourth Shift differ. So you can not know in a first time which computer system is right.

It is a real issue because this labour variance is useful to know if the production costs are closed to those which were expected. Without this labour variance you ca not know if a line works well or not.

To try to discover the issue source, figures from Period 12 have been analysed both in Probase and Fourth Shift, using the “Orders by period” sheets, the daily production report, documents based on Fourth Shift data, supervisors’ sheets and “end of order” sheets.

The supervisors’ sheets5 are completed by the supervisor of each line. They have to indicate details concerning the quantity of products filled the damaged products, and the number of operators… Basically they have to write all the details concerning the production on their line. They complete this kind of sheet every shift.

The “end of order” sheets6 are completed when an order is closed. On this sheet is indicated all the labour hours used and the number of operators which have been necessary for the order. This kind of sheet is also completed by a supervisor, the one who has finished the order.

To try to visualize where the mistakes could have been made, I schematized the information flows and indicated the people who influence Probase (PB) and Fourth Shift (4S).

5 example of supervisor sheet on Additional document II6

- 6 -

InformationProduction

(labour hours)

End of OrdersSheetsRobbie


This diagram shows that there are 4 potential mistakes for Fourth Shift whereas there are only 3 potentials mistakes for Probase.

The first step, before checking in depth if some mistakes have really been made (using the figures of Period 12),was to calculate the labour rate in each system to determine the values used. They should use the same value.

Then the operator hours in the two systems were checked and finally the costings were examined.

A. Calculation of the labour rate used in Probase and the one used in Fourth Shift

- 7 -

PROBASE FOURTH SHIFT

Supervisor’s sheet

costing

supervisors

supervisors

Kim or Jo

Orders by period

Daily production report

: potential mistake

Figure 2 : Information flows from the production lines to the computer systems


The labour rate is the cost of an operator working for one hour. So the first step is to check if the labour rate used by Probase is the same than the one used by Fourth shift.

1) a £11.00 labour rate used by Probase

Thanks to some figures written on the “orders by period” sheets (as the total filled, the costed UPOH7, the actual UPOH and the labour variance) the labour rate used in Probase could be calculated.

For example for the order number 362 305 (AVON MENS S/G):

Total filled: 120 960 Costed UPOH: 210.00 Actual UPOH: 455.30 Labour variance: £ 3413.70 *

Labour variance = Labour rate * (1/costed UPOH – 1/actual UPOH) * total filled

Labour rate = £ 11.00

The labour rate has been calculated for 10 samples and each time it was about £ 11.00. So the labour rate in Probase is £ 11.00.

2) a £11.00 labour rate used by Fourth Shift

For 4S, the labour rate could be calculated by using the labour used, and the operator hours as shown in 4S.

For example for the order number 362 442 (Mibelle SG LDY JANA):

Operator hours: 177h Labour used : £ 1,945.41

Labour used = Operator hours * Labour rate

So Labour rate= £ 10.99

The labour rate has also been calculated for 10 samples, on the basis of the figures recorded in Fourth Shift. Every time the labour rate was £ 10.99.

The labour rate in PB and the one in 4S is the same so it is not a source of mistake.

7 UPOH : Unit Per Operator Hour

- 8 -

B. Comparison between the Operator hours as shown in PB, those as shown in 4S and the real ones

One of the differences between Probase and Fourth Shift is the labour hours. To try to find the mistakes which have been made, the data of Period 12 was used. The Period 12 covers 4 weeks from the beginning of May. 154 orders were closed during this period. To compare the operator hours between PB and 4S, the “orders by period” sheets, which came from PB and some sheets whose figures came from 4S were used.

106 samples among the 154 orders of Period 12 were checked. For 45 samples, the operator hours recorded in PB and those recorded in 4S differed, giving an error rate of 42.5%.

Further analysis shows that most of these differences are not very significant. Differences:

< 5 h : 27 samples 5h -10h: 10 samples > 10h : 8 samples

Figure 3 : difference between the labour hours in PB and those in 4S

The difference between the operator hours in 4S and those in PB is higher than 10 for only 8 samples which represents 7.55%.

To understand the reason of these differences, 10 samples (listed below) from the 106 initial samples have been analysed.

Order n° Line Customer Difference between the op hours in PB

and 4S362 539 9B NEXT + 76.93362 649 11 NEXT + 55.86362 625 3 CUSSONS +15.35362 659 12 RB - 14362 646 10 KAPA - 10.99362 541 11 CUSSONS - 9.07362 654 12 RB - 6362 633 7 NEXT - 4.11362 657 12 RB + 3.98362 645 9B NEXT - 3.53

Table 2 : 10 samples selected

- 9 -

1) First step: compare the figures recorded in Probase to those written on the supervisor sheets

The operator hours written on the supervisor sheets have been compared to those recorded in Probase. The result of the analysis showed that 3 samples presented some differences.

Order number: 362 625 (CUSSONS, line 3)

Probase data Supervisor sheet data (18/05/04) 8

Start time

End time Mins break

Operators

10:30 10:50 0 811:10 11:30 0 812:40 14:00 0 814:00 21:15 45 821:15 22:00 0 806:00 14:00 45 8

14:00 15:30 0 8

“_ “: same figures as in PB

For the order n° 362 625, the last end time and the last minutes break have not been recorded correctly in Probase.

The end time is 17:45 on the supervisor sheet but only 15:30 in Probase. So the difference between the end time on the supervisor sheet and the end time in Probase is 135 min. Moreover the 20 mins break do not appear in Probase.

(135 min – 20 min break) x 8 op = 15.33h

15.33 hours are missing in Probase. Consequently the operator hours from Fourth shift (144.01h) are correct.

8 As we can see on the additional document II

- 10 -

Start time

End time Mins break

Operators

_ _ _ __ _ _ __ _ _ __ _ _ __ _ _ __ _ _ _

14 :00 17:45 20 8

Order number : 362 649 (NEXT, line 11)

Probase data Supervisor sheet data (21/05/04)9

“_ “: same figures as in PB

For this sample, one hour has not been recorded in Probase. As 10 operators worked during this hour, the number of operator hours missing in Probase is 10 hours.

Even if we consider this mistake, there is still a difference of 45.86 hours between Probase and Fourth Shift. Certainly another mistake has been made somewhere else.

Order number: 362 633 (NEXT, line 7)

Probase data Supervisor sheet data

(17/05/04 and 18/05/04))10

9 As we can see on the additional document III10 As we can see on the additional document IV

- 11 -

Start time

End time Mins break

Operators

22:00 02:30 20 515:00 17:00 20 518:00 19:30 25 506:00 08:30 0 608:55 09:30 0 609:30 14:00 20 914:00 21:00 45 906:00 14:00 45 914:00 22:00 45 922:00 06:00 45 206:00 13:00 45 8

Start time

End time Mins break

Operators

_ _ _ __ _ _ __ _ _ __ _ _ __ _ _ __ _ _ __ _ _ __ _ _ __ _ _ __ _ _ __ _ _ _

13 :00 14 :00 0 10

For the order n°362 633, they are two mistakes on the 17th May. The end times recorded in PB should be 13:45 and 00:00 instead of 14:00 and 23:59. There is also a mistake on the 18th May. The end time recorded in PB should be 13:45 instead of 14:00.

(15mins x 8op) + (1min x 9ops) + (15mins x 9ops) = 4.4 hours

So for this order, about 4.4 operator hours have been incorrectly recorded in Probase. Fourth Shift is right (181.33 op hours).

Order number: 362 645 (NEXT, line 9B)

Probase data Supervisor sheet data11

(18/05/04)

The result of the comparison between the time taken based on the Probase data and the time taken based on the supervisor sheet data shows that it differs on Tuesday the 18th May.

11 As we can see on the additional document V

- 12 -

Start time

End time Mins break

Operators

_ 13 :45 _ __ _ _ __ 00 :00 _ __ 13:45 _ __ _ _ _

Start time

End time Mins break

Operators

06:20 14:00 45 814:00 22:00 45 823:40 23:59 0 906:00 14:00 45 914:00 14:30 0 8

Start time

End time Mins break

Operators

11:30 14:00 0 1514:15 16:00 0 1516:00 18:00 15 1418:00 20:30 15 920:30 22:00 15 16

Start time

End time Mins break

Operators

_ 13 :45 _ __ _ _ __ _ _ __ _ _ __ _ _ _

The end time 14:00 has been recorded in Probase instead of 13:45. 15 minutes, which do not appear on the supervisor sheet, have been recorded in Probase.

15 min x 15 op = 225 min = 3.75 h

So for this order, about 3.5 operator hours have been incorrectly recorded in Probase. Fourth Shift is right (777.41 op hours).

The result of the comparison between the supervisor sheets and the PB data shows that 4 mistakes have been made in the recording of information.

Order n° Line Customer Difference Reason ofMistake

362 539 9B NEXT + 76.93362 649 11 NEXT + 55.86 When recorded in

Probase

362 625 3 CUSSONS +15.35 When recorded in Probase

362 659 12 RB - 14362 646 10 KAPA - 10.99362 541 11 CUSSONS - 9.07362 654 12 RB - 6362 633 7 NEXT - 4.11 When recorded in

Probase362 657 12 RB + 3.98362 645 9B NEXT - 3.53 When recorded in

ProbaseFigure 4 : incorrect samples and reason of mistakes

2) Second step: compare the figures written on the supervisor sheets to those written on the end of order sheets.

- 13 -

From the analysis of the available documents it can seem that some mistakes have been made from the beginning; that is to say on the supervisors sheets.

This is what happened to the order number 362 657, 362 646 and 362 654. These mistakes are about the number of minutes run.

Order number: 362 539 (NEXT, line 9B)

Number ops

Number mins run

End of order sheet figures

Supervisor sheet figures

Difference

13 170 --- 010 435 0 43512 415 --- 011 195 --- 09 320 29012 303 30 --- 04 20 --- 03 255 --- 01 165 --- 02 150 --- 0

435mins x 10ops + 30min x 9ops = 77h

So the operator hours recorded in Fourth Shift are 77h higher than the real ones.

Order number : 362 649 (NEXT, line 11)

Number ops

Number mins run

End of order sheet figures

Supervisor sheet figures

Difference

5 165 --- 05 250 --- 06 185 --- 09 250 --- 0

12 As we can see on the additional document XI

- 14 -

9 435 375 609 435 --- 09 435 --- 09 60 0 6010 60 --- 08 435 37513 602 435 --- 0

For this order, 3 mistakes have been made by copying the figures from the supervisor sheets to the end of order sheet.

(60 mins x 9ops) x 2 + 60 x 8 =1560 min = 26 h


Order number : 362 659 (RB, line 12)

Supervisor sheet data (24/05/04)14

The number of minutes recorded is incorrect. It should be 345 instead of 240 mins. So the correct total mins run is 300.

For this order there is also an additional mistake on the end of order sheet. The supervisor wrote 195 mins run (240 – 45 mins breaks) instead of 300.

So finally the difference between the mins run written on the end of order sheet and the real figure is 105 min (300 – 195).

105 min x 8ops = 840 min = 14h


Some other mistakes have been made when the information from the supervisor sheets have been transferred to the end of order sheet. Some hours have not been correctly copied.

Order number : 362 646 (KAPA, line 10)

13 As we can see on the additional document X14 As we can see on the additional document IX

- 15 -

Start time

End time N° of mins

Mins break

Operators Total mins run

7 :30 13 :15 240 45 8 245


The number of mins is incorrect. It should be 120 mins instead of 60. So the total mins run is incorrect too.

Consequently on the end of order sheet 60 mins are missing.60 mins x 11 = 660 mins = 11 h

Concerning the operator hours, 11h are missing in Fourth Shift.Probase is correct (248.57 op hours).

Order number: 362 541 (CUSSONS, line 11)

The last mistake has been made by recording the figures in Fourth Shift. The number 315 has been recorded instead of 375.

60 mins x 9 ops = 9h

So 9h too much have been recorded in Fourth Shift.



Here the number of mins has been mistaken for the Total mins run (375 instead of 420). It resulted in a mistake on the end of order sheet. When the supervisor wrote the total mins run on the end of order sheet, he wrote 330 min (375 – 45 mins break) instead of 375 min (420 – 45 mins break).

45 mins were missing on the end of order sheet.

45 min x 8 op = 360 min = 6h

15 As we can see on the additional document VII16 As we can see on the additional document VIII

- 16 -

Start time


Mins break


20 :00 22 :00 60 0 11 60

Start time


Mins break


13 :00 20 :00 375 45 8 375

Concerning the operator hours, 6h could not be recorded in Fourth Shift.



The number of mins is incorrect because it should be 390 mins instead of 420. So the total mins run is also incorrect. It should be 340 mins instead of 370.

Consequently the operator hours written on the end of order sheet are also incorrect.

30 mins x 8 ops = 4 h

4 hours have been added by mistake on the supervisor sheet. These have also been added on the end of order sheet and subsequently input incorrectly into Fourth Shift.

In this case the operator hours in Probase (56.66 h) are correct.

Order n° Line Customer Difference Reason ofMistake

Systemwrong

362 539 9B NEXT + 76.93 Mins runC

4S

362 649 11 NEXT + 55.86Probase

RMins run

C

PB

4S

362 625 3 CUSSONS +15.35 ProbaseR

PB

362 659 12 RB - 14Mins run

CaMins run

C

4S

362 646 10 KAPA - 10.99 Mins runCa

4S

362 541 11 CUSSONS - 9.07 Fourth ShiftR

4S

362 654 12 RB - 6 Mins run 4S

17 As we can see on the additional document VI

- 17 -

Start time


Mins break


19 :15 01 :45 420 50 8 370

C362 633 7 NEXT - 4.11 Probase

RPB

362 657 12 RB + 3.98 Mins runCa

4S

362 645 9B NEXT - 3.53 ProbaseR

PB

Table 3 : Summary of investigations into hours discrepancies

Mins run C: mistake when the mins run have been Copied from the supervisor sheet to the end of order sheet

Mins run Ca: mistake when the mins run have been Calculated by the supervisors

Probase R: mistake when the labour hours have been Recorded in Probase

Fourth Shift R: mistake when the mins run have been Recorded in Fourth Shift

Most of the mistakes are about the mins run. Either they have not been correctly calculated or they have not been correctly copied on the end of order sheets. Unlike Fourth Shift, Probase does not need to know the minutes run. It calculates them itself based on the start time, the end time and the mins break. That is why PB presents fewer mistakes than 4S.

The operator hours of 7 samples are incorrect in Fourth Shift. Only 4 are incorrect in Probase. So we could think that Probase is more accurate and reliable than Fourth Shift. But actually, it is not the Probase system or the Fourth Shift system themselves which have to be

- 18 -

challenged because the mistakes (found in the results of these two systems) are due to the information recorded (which was incorrect or incorrectly recorded). So we can not say if one system is more accurate than the other.

We can only say that Probase results are more accurate than Fourth Shift results because the information recorded in Probase is more accurate than those recorded in Fourth Shift. It is the information source which generates the problems. In summary, the line supervisor information is not very accurate.

3) Suggestions to reduce the number of mistakes

Mistakes, such as those which arise when figures are recorded into a system, can not be easily avoided. If figures are recorded by a person, there is always a risk of mistake.

A way to reduce the risk to forget to record some hours could be to systematically tick on the supervisor sheets the hours which have just been recorded. In this way it may be easier and quicker to check if all the hours have been recorded. After having recorded the hours, the head supervisor could just have a look at the supervisor sheets to check if all the hours have been ticked that is to say recorded.

Most of the mistakes are about the minutes run (when they are calculated and when they are copied on the end of order sheet). This kind of mistake affects Fourth Shift.

One possibility to avoid the mistakes concerning the operator hours may be to record the operator hours calculated by Probase in Fourth Shift. Instead of using the end of order sheets which include two risks of mistakes concerning the operator hours, Robbie could use a report based on the operator hours calculated in Probase.

Information flows and potential mistakes(using the proposed system)

- 19 -

InformationProduction

supervisors

costing

There are still 4 risks of mistakes concerning Fourth Shift but their likelihood is lower. Most of the mistakes concerning the operator hours can be avoided in this way. For example, of the 12 mistakes found in the 10 samples chosen, 7 could be avoided in this way.

Actual system suggestion

Mins run calculated 4 mistakes 0 mistakes

Mins run copied 3 mistakes 0 mistakes

Information recorded in Probase

4 mistakes 4 mistakes

Information recorded in Fourth Shift

1 mistake 1 mistake

Table 4 : comparison between the actual system and the suggestion

Of course, by adopting this alternative system, the mistakes made by recording in Probase would be transferred to Fourth Shift. So Fourth Shift results could not become more reliable than Probase results. But they could, all the same, become more reliable than they were and more consistent with Probase results.

- 20 -

PROBASE

FOURTH SHIFT

Supervisor’s sheet

costing

Kim or Jo

Robbie

Orders by period

Daily production report

Report including the operator

hours

: potential mistake

Order n°(samples currently wrong)

362539

362649

362625

362 659

362 646

362 541

362 654

362 633

362 657

362645

Reason of

mistakes made

with the actual system

Mins RunC

ProbaseR+

Mins runC

ProbaseR

Mins runCa+

Mins runC

Mins runCa

Fourth Shift

R

Mins runC

ProbaseR

Mins runCa

ProbaseR

Samples still

wrong with the

suggested way

Table 5: improvements produced by the suggested way

- 21 -

This diagram shows that if the “time taken” (the number of minutes run) calculated by Probase was used to record the information in 4S, only 5 samples of the 10 samples which are currently incorrect would be still incorrect in 4S or both in PB and 4S. In this case, the number of incorrect samples would be cut by half.

C. Comparison between the costing recorded in PB and those recorded in 4S

Labour variance = Labour costed – Labour used

Labour used = (Total filled / actual UPOH) * 10.99Labour costed = (Total filled / costed UPOH)* 10.99

The calculation of the Labour used both in Probase and in Fourth Shift has already been checked. But the mistakes made by calculating, copying or recording the operator hours are not enough to explain the difference between the labour variances in Probase and those in Fourth Shift. Another factor influences the calculation of the labour variance. It is the costed Labour.

So the costed Labour based on the figures recorded in Probase has been compared to the costed Labour as shown in Fourth Shift. 40 samples were checked. It aimed to have one sample for each kind of product.

- 22 -

Table 6 : differences in the Labour variance between PB and 4S

The above pie chart shows that most of the samples (70 %) present a low level of discrepancy. (Difference between PB and 4S less than £100).

But 3 samples present a considerable difference (more than £1001).

Labour costs are not recorded in PB and 4S at the same time or by the same person. This presents a source of mistake. Another reason for potential error is the way in which some labour costs have been modified in one system but not in the other.

Ordernumber

Customer/Product

Line Costed UPOH DifferenceCosted UPOH PB/4S

DifferenceLabour Costed

PB/4SPB 4S

362 440

IBA CarpetFoam P/Haze 8 152.7 89.9984799 62.7015201 -2 395.12741

362 639CART Nair

Rose 8 190.9 141.810061 49.0899393 -201.545034

362 734 BHI CRK F/Toner 8 84 152.721697 -68.7216974 1 577.54857

362 331 NEXT J/P edt 9B 32 33.5983287 -1.59832868 411.8975

362 431 NC H Hands 9B 93.3 67.1927758 26.1072242 -214.23672

362 53918 NEXT Black 9B 44.8 33.5983105 11.2016895 -1 190.18286

- 23 -

MiniI A/S

362 442 MIBELLE Ladies S/G

10 210 193.891139 16.1088605 -127.427619

362 443KAPA S/Gel

Lady10 180 167.985645 12.0143546 -100.26

362 64619 WS S/Gel 10 210 179.997111 30.0028891 -513.455714

362 740BCM S/Gel

FCUK10 210 190.926645 19.0733552 -203

362 741CULV V05

gelle10 210

175,016987 34,983013 -316.334762

362 649

NEXT JPB Cream

11 60 46.6672437 13.3327563 -770.2520

Table 7 : 12 samples where Labour variance in 4S is more than £ 100 higher or lower than in PB

12 samples within the 40 samples checked (30%) showed a difference in the costed Labour between Probase and Fourth Shift higher than £ 100.

There are two samples among these 12 samples which had already been selected before to check the operator hours. A further analysis was made to check if the differences concerning the labour variances were due to both the mistakes in the operator hours and those in the costed Labour. The purpose was to check if there were not other mistakes somewhere else and if the two systems (4S and PB) worked correctly.

Order number

Difference between the labour variance in PB and the one in 4S

Difference Labour costed PB/4SBefore any checking After having checked

and corrected the operator hours

362 646 - £ 639.59 - £ 516.09 - £ 513.46

362 539 £ 347.13 - £ 1192.12 - £ 1190.18

For these two samples, the difference between the labour variance in PB and the one in 4S (calculated after having corrected the operator hours) is equivalent to the difference between the costed labour recorded in PB and the one recorded in 4S. It means that the overall

18 additional document XII19 additional document XIII20 Calculation made using excel

- 24 -

differences between the labour variance figures can be explained by the errors associated with the operator hours and the costed labour and from nothing else.

To reduce the number of mistakes in the costed Labour, a possibility would be that only one person records simultaneously the figures in the two systems (PB and 4S). Maybe this way would avoid important mistakes (>£1000) about the costed Labour and consequently about the labour variance.

D. A way to reduce the number of mistakes: using a Probase report to record the production figures into Fourth Shift

This analysis shows that there is not just one source of mistakes but several. Some mistakes are due to incorrect calculations, others to incorrect recording, others to incorrect copying, and others to different costings. But the interesting point is that most of the mistakes concern the minutes run (when they have been calculated or when they have been copied on the end of order sheet).

Probase, which calculates itself the mins run based on the start time, the end time and the minutes break, avoids this kind of mistakes.

Unlike Probase, Fourth Shift needs to know the mins run. That’s why Fourth Shift results present more mistakes than Probase results. The mins run calculation and copy is the main problem and Fourth Shift is the only system affected by it.

So in order to reduce the mistakes concerning the labour variances, the following recommendations can be useful:

- 25 -

1) Make line supervisors know the need to greater accuracy with the recording of line running data.

2) Develop a Probase report that gives a summary of the greater minutes run by order.

3) Use this information to input labour used into 4S.

4) Review the systems by which labour costings are entered into Probase and Fourth Shift to determine how to minimise discrepancies.

These analysis results don’t really correspond to the expected (guessed) results. It was thought that the main problem was a recording problem.

The way to use the PB results to record the information in 4S is going to be applied. It’s difficult to reduce more the number of mistakes because the information has to be recorded in a computer system. And when the information is recording by anybody, there is always a risk of mistake.

Probase and Fourth Shift are two computer systems used to manage production data. To manage the maintenance, another computer system is used. It is called Frontline. But all its options had not been explored yet. So investigate how to use these options, as customizing a report, or developing the preventive maintenance has to be done to optimize this software use.

III.III. INVESTIGATE HOW TO DEVELOP THE USE OF THEINVESTIGATE HOW TO DEVELOP THE USE OF THE MAINTENANCE MANAGEMENT SYSTEMMAINTENANCE MANAGEMENT SYSTEM

A computerised maintenance management system, called frontline, is used to organize tasks to do. It has been designed as a comprehensive asset management system. The asset register holds a record of anything that needs to be looked after and maintained or periodically checked. An asset is for example a building, a service such as ventilation, or equipment. The tasks which have to be done, the date they have to be done, and the people who are required can be recorded in this system. Some tasks are planned and have to be achieved for instance every week. Some others, as the breakdowns or the corrective maintenance, are unexpected. All theses tasks concerning the assets are put together. That’s what is called a “backlog”.

A. Design a new weekly work schedule report

- 26 -

Every week about 30 people need a work schedule which lists all the tasks to do in the week. As this weekly schedule is used by quite a few people, it has to show only the main information and to be as clear as possible.

The computer system proposes a few standard reports to list any information. But the one concerning the weekly work is a bit messy and not very easy to read. But standard reports are not the only solution. Actually the computer system offers the possibility to create your own variations of the standard reports to satisfy your own particular requirements. Items of the data which are shown on the report can be changed. But the data presentation can also be modified.

The standard report currently used shows much useless information as the department, the site, the status of the task, or the work type21. People who need the work schedule don’t need this data or already know them. So in order to work more quickly and more efficiently, it is important to show only the most important information. These important data are:

Work order Work description Asset No Planned Persons Planned Team Estimated Time Priority Total estimated Time

Actually this work schedule is useful for the technicians. So it is important for them to know immediately what they have to do just by having a quick look on this schedule. It is also useful to be able to do a search whether by planned person or by planned team.

Using the options offered by the system, a report including only the essential data has been design22.

B. Investigate the Resource planning use possibility

It would be interesting to have the possibility to use a resource planning that is to say to record in the system the labour hours of the technicians every week. 8 technicians work in the engineering department. They are divided in 3 groups:

Services fitters (3 persons) Electricians (4 persons) Facilities (1 person)

Each person works 39 hours/week. But sometimes someone is ill or on holiday. That is why it would be interesting to be able to record these kinds of events for the system to know the number of available labour hours for each week. As a result the system could organise the weekly schedule without exceeding the available number of labour hours.

As it was not easy to find the resource planning in the system, it was decided to call “Frontline”, to know if this option existed. But unfortunately the resource planning is not yet 21 As we can see on the additional document XIV22 As we can see on the additional document XV

- 27 -

available. A lot of people have already asked Frontline about it. The resource planning is being creating but it is not sure it will be available at the end of the year.

C. Develop Fault Codes to be able to do some Preventive Maintenance

When a machine has been repaired, when a problem concerning an asset has been solved, it is recorded in the system. It is “signed off”. But at the moment, these failures are not recorded according the kind of the fault and the kind of the action chosen to solve it. So there is no background history where you can find for instance all the sort of events concerning the equipment which happened during the last year.

This background history can be very useful because having a look on it can help to notice the most frequent problems. Subsequently it is easier to try to reduce the number of failures by doing some preventive maintenance. Most equipment failures are avoidable and result from too little preventive maintenance. Preventive maintenance can provide benefits if it is properly applied and if it truly prevents failures, reduced costs and downtime, and improves uptime, productivity and profits. The best way to do it is to inspect and detect the pending failures before they happen, to repair the defects, to monitor the performance conditions and the failure causes and to access the equipment on a fixed interval basis only if no better means exist.

At present, most maintenance is corrective. Repairs are always needed. However, better improvement maintenance and preventive maintenance can reduce the need for emergency corrections. The challenge is to detect incipient problems before they lead to total failures and to correct the defects.

So to be able to do some preventive maintenance, a fault register has to be created. So each failure could be associated with a fault area, a fault code but also an action code. The following are examples of areas where a failure can happen:

Motors Pumps Tank Industrial doors Pipes Gearbox Conveyor

The following are typical factory kinds23 of fault:

Abrasion Abuse Age deterioration Bond separation Consumable Depletion

23 Preventive Maintenance, J.D Patton, p16

- 28 -

Wear Fatigue Friction Operator Negligence Puncture Shock Stress

Contamination Corrosion Dirt Vibration

There are also some typical actions24 which can be done to solve the equipment issues:

Adjust/align Calibrate Consumables Diagnose Remove Remove and replace Remove and reinstall Install Inspect

The codes associated to these areas, faults and actions are going to be used every time a work order will be signed off.

Report: percentage by work type

It could be useful to be able to know the percentage of completed work orders by work type. But unfortunately, the modifications allowed on the Frontline Software are quite limited. The only way to achieve this idea would be to change the computer program of the software.

IV.IV. RAW WATER SUPPLY DESIGN STUDYRAW WATER SUPPLY DESIGN STUDY

A. The engineering department

To take care of all the machines on the lines, but also of the pipeworks, the electrical supply, the gas plant, and other things concerning the factory work, some engineers are required.

The engineering department can be divided in two sections:

The plant engineering The line engineering

The line engineering includes all the machines on the lines whereas the plant engineering includes the electricity, the gas plant… N. Fisher supervises both the plant engineering and the line engineering. A line Engineering Manager, M. Perry, supervises 17 line engineers (who work in the morning, in the afternoon or in the night) and a Plant engineer, C. Bundy, who supervises 3 electricians, 4 mechanical engineers, and one building facilities man.

24 Preventive Maintenance, J.D Patton, p16

- 29 -

Refurbish Rebuild Lube Modify Preventive Maintenance Repair Train Not completed Not known

Temperature Extremes Preventive maintenance

This engineers team is involved in an important project concerning a new water purification plant. To know if the actual pipework will be able to supply this new water treatment plant some calculations have to be made.

B. Check if the actual pipework can supply the new water plant system

Water is a raw material used to manufacture most of the products of this factory. But this water has to be purified before using it. It is a customers’ requirement. As customers’ requirements concerning water quality are becoming more and more important, the company decided to replace their actual water purification system which is called a deionised water system. It is their biggest project for the year 2004-2005. Actually the cost of the new water purification system is about £ 353,000.00. The engineers are working on this project which will be achieved at the end of November.

This new water purification system will have to be connected to each manufacturing room because pure water can be needed in each of them. This new system is based around the use of Reverse Osmosis (RO), as the main water purification method.

Some pipes, which are currently used to supply the deionised water plant, are going to be used to supply the new one. So it is useful to know where they are currently located. The diameter of a pipe can vary. Some pipes are 3 inch pipes, some others are 2 inch pipes, and we can also find some 1inch pipes. To supply the new water plant, some of them will have to be rerouted.

The pipework which is going to supply the new water plant has to respect some indications. So some parameters as the velocity of the flow which runs in the pipework and the pressure drop are important to know.

One part of the actual network is a 2” pipework. The other part is a 3” pipework. So the water velocity and the pressure drop have been calculated for these two parts.

1. Features of the 2 inch pipework (52 mm)

1) Calculation of the water velocity (2”pipework)

The water velocity for the 2 inch pipework supplying new water plant has to be calculated to check if it is about 2m/s as suggested. Actually 2m/s is a good velocity for liquid flow in a pipe. At speeds greater than this, the flow becomes noisy and erosion will increase.

The rate of the water flow is known. It is about 10 m3/h. So W = 10,000 kg/h

The diameter of the pipe and the density of the water are also known. d = 52 mm ρ = 965 kg/m3

The water velocity can be found by different ways: by using a nomograph, a formula or a computer program.

- 30 -

First way : read the water velocity on the nomograph which is a graphical solution of the formula written on the last page

On the nomograph, the water velocity is about 1.3 m/s.

Second way : calculate with the following formula:

v = 1273.2 x 103 q / d² = 21.22 Q / d² = 353.7 W / (d² x ρ)

v = velocity [m/s] d = Internal diameter of pipe [mm]q = Rate of flow [m3/s]Q= Rate of flow [L/min]W = Rate of flow [kg/h]ρ = Density [kg/m3]

v = 353.7 x 10 000 / (52² x 965) v = 1.35 m/s

Third way : use software

Another way to know the water velocity is to use software which calculates this velocity based on some data as the rate of water flow, the diameter of the pipe and the density.

From this information, the software found a water velocity which is 1.31 m/s.

The water supply specification requires a water supply pressure of at least 2 bars25

. So the pressure drop has also to be calculated to be sure that the water supply satisfies this requirement. To achieve this calculation it is necessary to know the pipe length but also the number of bends, valves and “tees”. A way to know this information is to go to see the pipework and to take direct measurements from the pipes. Some bends and valves are quite hard to see because the pipework goes sometimes through the roof. Even by climbing a ladder it’s hard to see something just under the roof because it’s very dark and quite messy. A sketch of the pipework is useful to remember all the bends and valves.26

2) Calculation of the Pressure drop (with a membrane valve)

25 Customer utilities, additional document XVI26 As we can see on the additional document XVII

- 31 -

Δp = ρ x g x Δh + (f / Di) x L total pipework x 0.5 x ρ x v²

L total pipework = L pipe + Leq

L pipe: the pipe length without considering bends valves and “tees”.Leq: the equivalent length of all the other elements.

2” Pipework total length

The 52 mm pipework length is about 158m. This pipework includes:

21 bends at 90° ( Leq / Di = 20 m each) 1 bend at 45° ( Leq / Di = 16 m each) 1 tee (flow straight through) ( Leq / Di = 20 m each) 1 membrane valve ( Leq / Di = 200 m each)

So Leq = (21 x 20 + 16 + 20 + 200) x 0.052 = 34.112 m L total 2” pipework = 158 + 34.112 = 192.112 m

Friction Factor

To calculate the pressure drop it is necessary to calculate first the Reynolds number to know the friction factor.

Re = 1273 x 103 x q x ρ / (d x μ) = 21.22 x Q x ρ / (d x μ) = 354 x W / (d x μ)

μ is the viscosity. The water viscosity is known. It’s 0.31.So the Reynolds number can be calculated.

Re = 354 x 10 000 / (52 x 0.31) = 219 602.97

Re > 2000 so the water flow is turbulent.The friction factor can be read on the nomograph which is a graphical solution of the

formula. f = 0.021

Pressure drop

The pressure drop can now be calculated thanks to the formula below:

Δp100 = 0.5 x f x ρ x v² / d = 62 530 f x W² / (d5 x ρ)

So Δp100 = 0.5 x 0.021 x 965 x 1.47² / 52 = 0.42 bars

- 32 -

Δp192.112= 0.81 bars

On the nomograph, the pressure drop read (for 100m) is about 0.32 bars.So Δp192.112= 0.62 bars

The software can also calculate the pressure drop. But unlike the formula used above, it takes the surface roughness into account. That’s why the result given by the formula and the one given by the software are not exactly the same. The software should be more accurate because it takes this parameter into account.

The steel pipes installed in the factory have already been used for a long time. So the surface roughness is 0.2 mm.

So according to the software, the pressure drop for 192.112 m is about 0.87 bars.

Formula Nomograph Software

Δp100 0.42 bars 0.32 bars 0.45 bars

Δp192.112 0.81 bars 0.62 bars 0.87 bars

Table 8 : Pressure drop for the 52 mm pipework with a membrane valve

3) Calculation of the Pressure drop (with a ball valve)

If the valve is a ball valve instead of a membrane valve, the total pipe length is 182.65 m instead of 192.112m.



Δp182.65 0.77 bars 0.58 bars 0.83 bars

Table 9 : Pressure drop for the 52 mm pipework with a ball valve

2. Features of the 3 inch pipework (80 mm)

- 33 -

1) Calculation of the Water velocity

The water velocity depends on the pipe diameter. On this pipework, the diameter of the pipes is not the same everywhere. Some pipes are 1 inch pipes, some others 1.5 inch pipes. So the water velocity is not everywhere the same.

v = 1273.2 x 103 q / d² = 21.22 Q / d² = 353.7 W / (d² x ρ)

W = 1,643 kg/h (maximal flow rate measured when the bath test of line 10 was being fully filled)

ρ = 965 kg/m3


Velocity for a 1 inch pipe

(d =27 mm)

v = 353.7 x 1 643 / (27² x 965)

v = 0.83 m/s0.85 m/s 0.80 m/s

Velocity for a 1.5 inch pipe

(d =40 mm)

v = 353.7 x 1643 / (40² x 965)

v = 0.38m/s0.35 m/s 0.36 m/s

Table 10 : water velocity for a 1 inch pipe and a 1.5 inch pipe given by the formula, read on the nomograph and given by the computer program

2) Calculation of the Pressure drop (with membrane valves )

This pipework is composed of 1 inch pipes and 1.5 inch pipes. The 1 inch pipe length is about 81.5 m whereas the 1.5 inch length is about 10.5 m.

The 1 inch pipework

Total 1’pipework length

The 1” pipework includes:

10 bends at 90° (Leq / Di = 20 m each) 1 bend at 45° (Leq / Di = 16 m) 3 “tee” (flow straight through) (Leq / Di = 20 m each) 1 tee (flow through side outlet) (Leq / Di = 65 m) 1 membrane valve (Leq / Di = 200 m)

So Leq = (10 x 20 + 16 + 3 x 20 + 65 + 200) x 0.027 = 14.61m

- 34 -

L total pipework = 81.5 + 14.61 = 96.11m

Friction factor

To calculate the pressure drop it is necessary to calculate first the Reynolds number to know the friction factor.

Re = 1273 x 103 x q x ρ / (d x μ) = 21.22 x Q x ρ / (d x μ) = 354 x W / (d x μ)

μ is the viscosity. The water viscosity is known. It’s 0.31.So the Reynolds number can be calculated.

Re = 354 x 1643/ (27 x 0.31) = 69 488.89

Re > 2000 so the water flow is turbulent.

The friction factor can be read on the nomograph which is a graphical solution of the formula.

f = 0.025

Pressure drop


Δp100 Δp100 = 0.5 x 0.025 x 965 x 0.83² /27

Δp100= 0.31 bars 0.3 bars 0.42 bars

Δp96.11 0.30 bars 0.29 bars 0.40 bars

Table 11 : Pressure drop for the 1’ pipework with 2 membrane valves

the 1.5 inch pipework

Total 1.5” pipework length

The 1.5” pipework includes:

5 bends 90° (Leq / Di = 20 m each)

- 35 -

2 “tee” (flow straight through) (Leq / Di = 20 m each) 1 membrane valve (Leq / Di = 200 m)

So Leq = (5 x 20 + 2 x 20 + 200) x 0.040 = 13.6 m L total pipework = 10.5 + 13.6 = 24.1 m

Friction factor

Re = 354 x 1 643 / (40 x 0.31) = 46 905

Re > 2000 so the water flow is turbulent.The friction factor can be read on the nomograph which is a graphical solution of the

formula. f = 0.025

Pressure drop

Table 12 :

Pressure drop for the 1.5” pipework with a membrane valve

So the maximal pressure drop for the 3” pipework (including membranes valves) is about 0.41 bars (= maximal pressure drop for the 1” pipe part + maximal pressure drop for the 1.5” pipe part).

3) Calculation of the pressure drop (with ball valves)

1 inch pipework

If the two valves included in this pipework are ball valves instead of membrane valves, the total pipe length is 91.2m instead of 96.11m.



- 36 -


Δp100 Δp100 = 0.5 x 0.025 x 965 x 0.38² /40

Δp100= 0.043 bars 0.038 bars 0.05 bars

Δp24.1 0.010 bars 0.009 bars 0.012 bars

Δp91.2 0.28 bars 0.27 bars 0.38 bars

Table 13 : Pressure drop for the 1’ pipework with 2 ball valves

1.5 inch pipework

If the valve included in this pipework is a ball valve instead of a membrane valve, the total pipe length is 16.82 m instead of 24.1m.


Δp100 0.043 bars 0.038 bars 0.05 bars

Δp24.1 0.010 bars 0.009 bars 0.012 bars

Table 14 : Pressure drop for the 1.5” pipework with a ball valve

So the maximal pressure drop for the 3” pipework (including ball valves) is about 0.39 bars (= maximal pressure drop for the 1” pipe part + maximal pressure drop for the 1.5” pipe part).

The velocity found for the 2”pipework is about 1.3 m/s. The pressure drop about this pipework does not exceed 0.9 bars. Indeed if there is a membrane valve in the pipework, the pressure drop is about 0.87 bars (software result) and if it’s a ball valve the pressure drop is a bit lower. It’s about 0.83 bars (software result).

As the calculated pressure drop is at worst 0.87 bar and the water pressure at supply point is 5 bar, the water pressure available at new treatment plant is about 4.13 bar (= 5 – 0.87 bar). The required water supply pressure is at least 2 bars. 4.13 bars is well inside the specifications. So this pipework seems to respect the required conditions to supply the new water treatment plant.

About the 3” pipework, the water velocity found is quite low. It is about 0.8 m/s for the 1” pipe part and about 0.36 m/s for the 1.5” pipe part. So the pressure drop is about 0.41 bars if we consider membrane valves and 0.39 bars if we consider ball valves.

Water is used in the test baths and to manufacture the products for example, but also to cool the tanks in the manufacturing rooms. Actually some products have to be cooled or heated to be mix properly. Some rooms are cooled by the cooling tower water whereas some others (rooms 1 and 2) are cooled by the mains water. The idea of one engineer would be to cool rooms 1 and 2 by cooling tower water because it is cheaper.

- 37 -

V.V. COOLING ROOMS 1 AND 2 BY COOLING TOWER COOLING ROOMS 1 AND 2 BY COOLING TOWER WATER: A CHEAPER SOLUTION?WATER: A CHEAPER SOLUTION?

Rooms 1 and 2, which are manufacturing rooms, are currently cooled by mains water, which is quite expensive. A way to reduce the cost of the cooling would be to cool these to rooms by water from the cooling tower. Actually with the current system used water goes to drain whereas with a cooling tower water is recycled. The company is charged for water coming on site and for water going to drain so it should be really cheaper to change the current system and to decide to use the cooling tower water. This way is already used for rooms 3 and 4.

Sketching the existing system

The first step (to know if this idea is feasible) is to sketch the existing system.2727

Mains water consumption cost for room 1 and 2

In 2003 the cooling water consumption for rooms 1, 2 and 4 was 16 825 m3. The half of this water quantity was used for room 4; a quarter was used for room 1 and another quarter for room 2. So the cooling water consumption for room 1 as well as for room 2 was about 4 206.25 m3.

The water used in the factory is provided by a private company. Each m3 of water coming on site is charged £ 0.97 and water going to drain is charged £ 1.44. It is considered that the quantity of water going to drain is 95% of the incoming water quantity.

Charge for incoming water :4 206.25 x 0.97 = £ 4080.06

Charge for water going to drain :95% x 4 206.25 x 1.44 =£ 5 754.15

Another cost has to be taken in account. It is the electricity cost. Actually the pump which is used to supply room 1 and 2 runs almost continuously (about 120 hours/week). The electricity cost is £ 0.04 by kW and by hour.

Chemical products are used to treat the cooling tower against the legionnaire disease. The electricity cost due to the pump use is equivalent to the chemical products cost. So the money saved by not using the electrical pump could be used to buy the chemical products for the cooling tower.

Cooling rooms 1 and 2 by the mains water costs about £ 19 668.42 by year if we only consider the water consumption. A cooling tower uses recycled water so the water consumption cost is nil. The cooling tower already runs to provide cold water to rooms 5, 6 and 7 for instance. So it seems obvious that using the cooling tower water to cool tanks in

27 As we can see on the additional document XIII

- 38 -

}} For each room: £ 9 834.21 (R1 and R2)

rooms 1 and 2 would make save money. Of course, using a cooling tower implies costs as those concerning the chemical

products used to treat the tower against the legionnaire disease. But they are minor compared to the water consumption costs calculated above.

So using the cooling tower water for room 1 and 2 seems to be cheaper. To check if this idea is feasible, the cooling load will have to be calculated.

- 39 -

CONCLUSIONCONCLUSION____________

Several issues have been analysed. The first analysis concerning the differences between the two computer systems Probase and Fourth Shift showed that most of the mistakes were due to incorrect minutes run calculation or their incorrect copy. This kind of mistakes affects particularly Fourth Shift. So a way to reduce the number of mistakes is to develop a Probase report that gives a summary of the greater minutes run by order and to use it to record the information in Fourth Shift. Another kind of mistake is about the costings. Further analysis should determine the reason of these discrepancies.

Concerning the new water purification plant, the calculation of the pressure drop in the 2inches pipework permitted to know that the water pressure available is about 4.13 bars which is inside the specifications. So this pipework respect the required conditions and can be used to supply the new water treatment plant.

A new weekly work schedule has been designed and is now used to inform technicians about the work they have to do during the week. Fault codes and action codes have been developed to be able to do some preventive maintenance. These codes will be useful to know the most frequent issues about the equipment and to try to find a solution to reduce their frequency. Unfortunately the resource planning can not be used because it is not available yet.

Finally, using the cooling tower water instead of the mains water to supply the rooms 1 and 2 is a really cheaper solution. Cooling load calculations are going to be made to make sure this idea is feasible.

- 40 -

BIBLIOGRAPHIEBIBLIOGRAPHIE________________

“Formulas and nomographs for flow through valves, fittings and pipe”, chapter 3, 3-6 to 3-12

“Mécanique des fluides: première partie”, Louisnard Olivier, cours de l’école des Mines d’Albi, Octobre 2003, p72-73

“Project: New Water Purification System and Distribution Ringmain”,Supplier’s specifications about the new water purification plant, 10th May 2004, site Aerosols International, Wellington, Somerset, ref 2031001F2/GO/COS

“Preventive Maintenance”, J.D Patton, Jr. 2nd Edition, The International Society for Measurement and Control, 1995, p1-31 (chap1:Major types of Maintenance, chap 2: Advantages and Disadvantages, chap 3: Designing a PM program)

http://progdev.sait.ab.ca/pwen220/074/cooling3.htm, “Mechanical draft cooling towers”, SOLIS (Southern Alberta Institute of Technology), 26/09/2002

“Plant Engineer’s Reference Book”, 2nd Edition, Dennis A.Snow, The institution of Plant Engineers, chap 21 cooling towers, p 21/3 to 21/15

- i -

http://progdev.sait.ab.ca/pwen220/074/cooling3.htm

ADDITIONAL DOCUMENTSADDITIONAL DOCUMENTS____________

ADDITIONAL DOC.I:ADDITIONAL DOC.I: Example of Daily Production Report (18/05/04)

ADDITIONAL DOC.II:ADDITIONAL DOC.II: Supervisor sheet: 18/05/04 (CUSSONS line 3)

ADDITIONAL DOC. III:ADDITIONAL DOC. III: Supervisor sheet: 21/05/04 (NEXT line 11)

ADDITIONAL DOC.IV:ADDITIONAL DOC.IV: Supervisor sheet: 17/05/04 (Next Line 7) Supervisor sheet: 18/05/04 (Next Line 7)

ADDITIONAL DOC.V:ADDITIONAL DOC.V: Supervisor sheet: 18/05/04 (NEXT line 9B)

ADDITIONAL DOC. VI:ADDITIONAL DOC. VI: Supervisor sheet: 23/05/04 (RB line 12)

ADDITIONAL DOC.VII:ADDITIONAL DOC.VII: Supervisor sheet: 17/05/04 (KAPA line 10)

ADDITIONAL DOC. VIII:ADDITIONAL DOC. VIII: Supervisor sheet: 21/05/04 (RB line 12)

ADDITIONAL DOC. IX:ADDITIONAL DOC. IX: Supervisor sheet: 24/05/04 (RB line 12)

ADDITIONAL DOC.X:ADDITIONAL DOC.X: Supervisor sheet 21/05/04 (NEXT line 11)

ADDITIONAL DOC.XI:ADDITIONAL DOC.XI: Supervisor sheet: 14/05/04 (NEXT line 9B) Supervisor sheet: 16/05/04 (NEXT line 9B)

ADDITIONAL DOC.XII:ADDITIONAL DOC.XII: Orders by period report for the line 9B (period 12) Order variance report for labour on orders completed (25/05/04)

(4S data)

ADDITIONAL DOC. XIII:ADDITIONAL DOC. XIII: Orders by period report for the line 10 (period 12) Order variance report for labour on orders completed (25/05/04)

(4S data)

ADDITIONAL DOC. XIV:ADDITIONAL DOC. XIV: Standard report about the work schedule

ADDITIONAL DOC.XV:ADDITIONAL DOC.XV: Customised work schedule report

ADDITIONAL DOC. XVI:ADDITIONAL DOC. XVI: Extract of the “Project: New Water Purification System and Distribution Ringmain”,Supplier’s specifications about the new water purification plant, 10th May 2004, site Aerosols International, Wellington, Somerset, ref 2031001F2/GO/COS

ADDITIONAL DOC. XVII:ADDITIONAL DOC. XVII: Sketch of the actual pipework

- ii -

ADDITIONAL DOC. XVIII:ADDITIONAL DOC. XVIII: Sketch of the actual system of cooling

ADDITIONAL DOCUMENT I:ADDITIONAL DOCUMENT I:

Example of Daily Production Report (18/05/04)

- iii -

ADDITIONAL DOCUMENT II:ADDITIONAL DOCUMENT II:

Supervisor sheet: 18/05/04(CUSSONS line 3)

- iv -

ADDITIONAL DOCUMENT III:ADDITIONAL DOCUMENT III:

Supervisor sheet: 21/05/04(NEXT line 11)

- v -

ADDITIONAL DOCUMENT IV:ADDITIONAL DOCUMENT IV:

Supervisor sheet: 17/05/04(Next Line 7)

- vi -

ADDITIONAL DOCUMENT V:ADDITIONAL DOCUMENT V:

Supervisor sheet: 18/05/04(NEXT line 9B)

- vii -

ADDITIONAL DOCUMENT VI:ADDITIONAL DOCUMENT VI:

Supervisor sheet: 23/05/04(RB line 12)

- viii -

ADDITIONAL DOCUMENT VII :ADDITIONAL DOCUMENT VII :

Supervisor sheet: 17/05/04(KAPA line 10)

- ix -

ADDITIONAL DOCUMENT VIII:ADDITIONAL DOCUMENT VIII:


- x -

ADDITIONAL DOCUMENT IX:ADDITIONAL DOCUMENT IX:


- xi -

ADDITIONAL DOCUMENT X:ADDITIONAL DOCUMENT X:

Supervisor sheet 21/05/04(NEXT line 11)

- xii -

ADDITIONAL DOCUMENT XI:ADDITIONAL DOCUMENT XI:



- xiii -

ADDITIONAL DOCUMENT XII:ADDITIONAL DOCUMENT XII:

Orders by period report for the line 9B (period 12)Order variance report for labour on orders completed (25/05/04) (4S data)

- xiv -

ADDITIONAL DOCUMENT XIII:ADDITIONAL DOCUMENT XIII:

Orders by period report for the line 10 (period 12)Order variance report for labour on orders completed (25/05/04) (4S data)

- xv -

ADDITIONAL DOCUMENT XIV:ADDITIONAL DOCUMENT XIV:

Standard report about the work schedule

- xvi -

ADDITIONAL DOCUMENT XV:ADDITIONAL DOCUMENT XV:

Customised work schedule report

- xvii -

ADDITIONAL DOCUMENT XVI:ADDITIONAL DOCUMENT XVI:

Extract of the “Project: New Water Purification System and Distribution Ringmain”,Supplier’s specifications about the new water purification plant, 10th May

2004, site Aerosols International, Wellington, Somerset, ref 2031001F2/GO/COS

- xviii -

ADDITIONAL DOCUMENT XVII:ADDITIONAL DOCUMENT XVII:

Sketch of the actual pipework

- xix -

ADDITIONAL DOCUMENT XVIII:ADDITIONAL DOCUMENT XVIII:

Sketch of the actual system of cooling

- xx -

- xxi -

MAINTENANCE

Improvement Preventive Corrective

On-condition Self-ScheduledMachine-cuedControl limitsWhen deficient As required

Condition Monitor Statistical Predictive Trend analysis

Scheduled PeriodicFixed IntervalHard timelimitsSpecific time

Unscheduled BreakdownEmergencyRemedialRepair

ModificationRetrofitRedesignChange order

- i -

COMPACT III RO Unit

UV disinfec

tion unit

Purified Water Tank

Raw Water Tank

Brine

Ozone Generator

Drain

Ozone in air detection monitor

Cartridge filter

Softeners

CIP Tank

Ozone destruct filter

- i -

WORKSHOP

QC AND DEVELOPMENT LABORATORY

MANUFACTURING ROOMS

COMPONENTSSTORES

LPG TANKS

Goods in checking

perso.imt-mines-albi.frjourneau/rapports/rt/rt aude mic… · web viewaerosols international...

Documents