paint spray room proposal
TRANSCRIPT
Paint Spray Chamber Proposal
Prepared by: Rajveer Singh (Intern)
Dates:
1) 10/8-12/8- Data collection and analysis
2) 13/8-14/8 Report typing and calculations
Supervisor: Yazid Adam
Acknowledgements and thanks to:
1) Ravi Govindan
2) Muhammad
3) Julie Alias
4) Anas Anafi
5) Robert Loh
6) Shamsul Kamal
7) Sugumaran
& the paint and masking crew
For providing me with data, information, advice, ideas and suggestions while completing this
proposal
Summary
Painting is the final part of the manufacturing process, and one of the most important. UPECA Aerotech
uses a manual painting system, in which a paint gun is filled with the paint that is to be used. This paint
is then sprayed onto the manufactured part at a relatively high pressure (6 bar). The process is
conducted in a spray chamber with a controlled environment to ensure optimal conditions for effective
painting. The spray chamber was designed such that only one type of product could be sprayed at any
one time, making sudden large batches of different products a complication.
The painting process in itself is long, and involves many steps. A detailed chart of the entire process can
be seen in appendix 1, while a summary of the steps and their functions can be seen in appendix 2.
Introduction
In recent weeks, the painting team has come to the conclusion that there are insufficient paint spray
chambers to cope with the demand of manufactured parts. As such, plans have been put in place to
build an additional spray chamber to ease the burden on the existing one.
However, since the capital and maintenance costs are high, further quantitative studies were required
to make a final decision as to whether an additional spray booth would increase overall productivity and
output, or merely operate at semi-capacity.
In order to come to a final conclusion, this study was conducted from two different angles, namely;
1) Efficiency and Usage of existing Spray Booth
2) Build up process to the part spraying (i.e. Part masking efficiency)
In addition to the above, a simplified economic analysis (with the limited data available) was also
conducted to project the expected maintenance, repairing and utility costs.
Justification of selection of factors of study
1. Efficiency of Spray Chamber
All the while, the paint team believed that the lack of a second spray booth was the reason that the rate
of production was slow. As such, the testing of the existing spray booth was done to see if it was
underused, and was delaying release of finished parts to the Final Quality Control department.
2. Part Marking Efficiency
The idea behind analyzing part masking efficiency was to see whether the rate of part masking was a
contributing factor to a reduced production rate. This was studied by considering the number of staff
attending to part masking, along with the projected rise with a larger staff number.
Literature Review
All aircraft parts that are manufactured in UPECA Aerotech are spray painted, in accordance to the
customer’s requirement. Some parts are sprayed with just a single layer (primer coat), while most parts
are sprayed with two layers (primer and top coats). Both coats of paint have their own functions, which
are stated below;
Primer Coat- Used to cover up any scratches or discontinuity on the surface of the part. Also used to
prevent rusting and corrosion.
Top Coat- Used to ensure the part is aesthetically pleasing.
A proposal has been put in place to build a new spray chamber, so that the existing one can be used for
spraying the primer coat, while the new one can be used to spray the top coat. This is done with the
intention of reducing waiting/idle time. The proposed new spray chamber will also serve as a backup,
should the existing one breakdown or require maintenance and repair. A study of two different factors
was conducted to see if an additional spray booth will have a positive effect on the efficiency of the
spraying process.
Table 1: Gantt chart of Analysis Dates
Day (Date)
Monday (10/8/15)
Tuesday (11/8/15)
Wednesday (12/8/15)
Efficiency of Painting Process
Efficiency of Part Masking Process
This was intentionally done so that both factors could be studied individually, and then together.
Due to the limited time that I had (as my attachment in the paint department was only for 2 weeks), this
data collection exercise could only be done over three days, as opposed to a longer period of time which
would have been more desirable.
Data Obtained
The study was conducted, data obtained and analyzed for the day shift of three consecutive weekdays,
in order to determine the efficiency of the existing spray booth. The results and calculations are shown
in the following pages
1) Efficiency of Existing Spray Booth
The results obtained were summarized in the table below:
Table 2: Spray Chamber Usage for 10/8/15
Material Batch Number Preparation Time (Minutes)
Painting Time (Minutes)
Number of Parts
1 15 44 198 (P)
2 12 29 198 (TC)
3 8 12 2 (P)
4 4 6 2 (TC)
5 10 12 3 (P)
6 8 16 3 (TC)
Total = 57 minutes
Total = 119
Total = 406
From the table above, total usage time of paint spray chamber is 57+119 minutes = 176 minutes
We will make an assumption that the working day is 8.5 hours = 510 minutes.
Justification: Working shift is 8.15a.m. – 5.45p.m. (9hours 30 minutes)
9:30 – 0:45(Lunch) – 0.15(Rest) = 8.5 hours
Hence, usage of paint spray chamber = (176/510) x 100%
= 34.5%
Note: This value is NOT equal to the efficiency of the spray chamber. Efficiency in this case is defined as
(actual usage/expected usage) x 100%. Since the expected usage is about 70%, the efficiency of the
existing spray chamber = (34.5/70) x 100% = 49.3%
Efficiency for Day 1= 49.3%
Table 3: Spray Chamber Usage for 11/8
Material Batch Number Preparation Time (Minutes)
Painting Time (Minutes)
Number of Parts
1 4 17 53 (P)
2 6 27 81 (TC)
3 6 9 11 (TC)
4 2 3 30 (TC)
5 15 20 53 (TC)
6 2 8 4 (P)
7 5 21 4 (TC)
Total = 40 minutes
Total = 105
= 236
Hence, total spray chamber usage time = 40 +105 = 145 minutes
Usage = (145/510) x 100% = 28.4%
Hence, efficiency = (28.4/70) x 100%
= 40.6%
Efficiency for day 2 = 40.6%
Hence, average efficiency of both days = (40.6+49.3)/2
Average efficiency = 45%
Index
Preparation Time:-
1) Time taken to push the trolleys of the parts into and out of the spray chamber to and from the
flashing and oven areas
2) Time taken to mix the and stir the paint in accordance to the required ratios
3) Time taken to wear and remove PPE.
4) Time taken to load the paint into the paint gun, and rinse it after use
Painting Time:-
The actual time that the parts are being sprayed with the paint.
P- Primer layer painting
TC- Top coat layer painting
Discussion
Day 1 efficiency = 49.3%
Day 2 efficiency = 40.6%
Average efficiency = 45%
Based on the datum recorded, the above values of efficiency were calculated. The average was also
calculated as well. It was noted that the efficiency for day 2 was almost 10% lower. Possible reasons for
this include:
1) The paint department leader was not around to push the team and lead the production.
2) Another regular member of the paint staff was also not around.
3) Support staff from other departments were brought in to make up for the reduced number of
workers. These support staff are not well trained in masking, and paint preparation and could have
slowed down the production.
As a whole, it is clear that the existing spray booth is not being utilised to the maximum capacity. An
average efficiency of 45% is indicative that there is further room for growth and improvement. This
value shows that the paint spray chamber “spends” more time idle, than being used. As such, it is not
recommended that an additional spray booth is added, until the efficiency can be boosted to the desired
value (~70%).
Steps that can be taken to increase efficiency of the existing spray booth:
1) Increase the number of staff at the masking area, so that the idle time can be slashed.
2) Request for a chart/timetable or some other form of indication (during the daily morning meetings)
from the plating and TSA departments of the expected quantity and timing of the parts arrival (for the
day) into the paint department, so that the paint crew is able to plan and delegate in advance. This will
lead to a smoother and faster painting preparation.
Conclusion
Building an additional spray booth is a large expense over a long period of time. In addition to that, the
construction period, which is estimated at 4 months, will cause disruption to the existing paint
operation, and potentially reduce the efficiency. Furthermore, the average efficiency of the spray booth
is a mere 45%. This figure does not warrant the expenditure that will come with an additional facility. As
such, the recommended course of action would be to focus on increasing the efficiency of the existing
spray booth, rather than building a new one. However, this idea must be revisited in future, when the
efficiency of the spray booth is in the range of 70-80%.
2) Part Masking Efficiency
Table 4: Part Masking for 11/8
Material Batch Number Duration (Minutes)
Number of Parts Marked
1 26 12
2 102 36
3 16 4
4 44 16
5 71 36
6 34 27
7 60 15
8 12 4
9 89 26
Total = 9 Batches
Total = 454 minutes
Total = 176 Parts
For the table above, it was thus calculated that the average time to mask 1 part as 2.6 minutes (454
minutes/176 parts). 5 staff members were present on 11/8.
Assuming that the total number of parts were the same, the following table was calculated and drawn. It
is obvious that a larger number of staff would lead to a lower total time for part masking. Ballpark
figures of 10%, 15% and 20% time reductions were used for 6 staff members, while 20%, 25% and 30%
reductions were considered for 7 staff members.
For the calculations that follow, the initial figure of 176 parts was retained as the total number of parts
masked over the course of the day. 454 minutes was also used as the total time spent on the masking
process.
Table 5: Predicted reductions in average time for 6 and 7 staff members respectively
5 Staff 6 staff 7 staff
Average number of parts marked per staff 35.2 29.33333 25.14286
Total time spent (Minutes) 454 N/A N/A
Actual time spent with percentage reduction in time (Minutes)
10% (20% for 7 staff) N/A 408.6 363.2
15% (25% for 7 staff) N/A 385.9 340.5
20% (30% for 7 staff) N/A 363.2 317.8
Average time per worker (Minutes)
10% (20% for 7 staff) N/A 68.1 51.88571
15% (25% for 7 staff) N/A 64.31667 48.64286
20% (30% for 7 staff) N/A 60.53333 45.4
Average Time per part (Minutes)
10% (20% for 7 staff) N/A 2.321591 2.063636
15% (25% for 7 staff) N/A 2.192614 1.934659
20% (30% for 7 staff) N/A 2.063636 1.805682
It is expected that the reduction in time will be 15% for 6 staff, and 25% for 7 staff.
Hence, the percentage reduction in time can be calculated as follows;
Table 6: Percentage reduction in average time per part for 11/8
Number of staff 5 6 7
Average Time Per Piece (Minutes)
2.6 2.2 1.9
Percentage reduction from original (%)
0 15.4 26.9
This translates to a 15.4% increase in efficiency for one additional member of staff, but a 26.9% increase
in efficiency for two additional members of staff.
Table 7: Park Masking for 12/8
Material Batch Number Duration (Minutes)
Number of Parts Marked
1 21 9
2 3 2
3 47 27
4 44 8
5 17 8
6 23 9
7 75 30
8 21 8
9 40 15
10 100 32
Total = 10 batches
Total = 391 minutes
Total = 148 parts
From the table, the average time to mask a single part was found to be = 2.6 minutes. 5 staff members
were present on 12/8.
The following table was then drawn, using similar calculation methods to those in table 5.
The calculated figure of 148 parts was retained as the total number of parts masked over the course of
the day. 391 minutes was also used as the total time spent on the masking process.
Table 8: Predicted reductions in average time for 6 and 7 staff members respectively
5 Staff 6 staff 7 staff
Average number of parts marked per staff 29.6 24.66667 21.14286
Total time spent (minutes) 391 N/A N/A
Actual time spent with percentage reduction in time (Minutes)
10% (20% for 7 staff) N/A 351.9 312.8
15% (25% for 7 staff) N/A 332.35 293.25
20% (30% for 7 staff) N/A 312.8 273.7
Average time per worker (Minutes)
10% (20% for 7 staff) N/A 58.65 44.68571
15% (25% for 7 staff) N/A 55.39167 41.89286
20% (30% for 7 staff) N/A 52.13333 39.1
Average Time per part (Minutes)
10% (20% for 7 staff) N/A 2.377703 2.113514
15% (25% for 7 staff) N/A 2.245608 1.981419
20% (30% for 7 staff) N/A 2.113514 1.849324
Similarly, it is expected that the reduction in time will be 15% for 6 staff, and 25% for 7 staff.
Hence, the percentage reduction in time can be calculated as follows;
Table 9: Percentage reduction in average time per part for 12/8
Number of staff 5 6 7
Average Time Per Piece (Minutes)
2.6 2.2 2.0
Percentage Reduction from Original (%)
0 15.4 23.1
This translates to a 15.4% increase in efficiency for one additional member of staff, but a 23.1% increase
in efficiency if two members of staff were to be added.
Discussion
The information obtained from both the days can be averaged and summarised into the table below;
Table10: Average reduction over 11/8 and 12/8
Number of staff 5 6 7
Average Time Per Piece (Minutes)
2.6 2.2 2.0
Percentage Reduction from Original (%)
0 15.4 25.0
The above table reads that one additional staff member into the paint department can increase the
efficiency by 15.4%, while two additional staff will increase it by 25.0%. This in turn will reduce the
masking and preparation time, before the parts are sprayed in the spray booth. Consequently, the idle
time of the spray booth (shown earlier to be around 4.7 hours per shift) can be cut.
Furthermore, an addition of a staff member will reduce the average time per piece by about 0.4 minutes
(24 seconds). Over 180 pieces, the daily average, that is a total of 1.8 man hours saved daily. Hence, it
can be said that the advantages of getting additional staff are:
1) Reduced man hours spent on masking. These saved hours can then be used in other activities within
the paint department, or event to support other divisions in production.
2) Enhanced efficiency of the spray chamber. An additional staff member will be able to reduce the idle
time of the spray chamber. It is hoped that an additional staff member will be able to reduce the idle
time of the spray chamber by 10-15% (to 3.7 hours). This in turn will increase the efficiency of the spray
booth to 56%.
Conclusion
The above calculations are an indication that the lack of a spray booth is not the reason for the delay,
but rather the slow delivery of the masking section to the spraying section. Hence, an investment on a
spray booth is not necessary, as the overall efficiency will not be boosted. However, it is recommended
that one additional member of staff be commissioned to join the masking division of the paint
department so that the average time can be reduced.
The cost of adding two members of staff will be 2x the cost of adding a single member. In order for this
investment to be warranted, the increase in efficiency for two additional members should be no less
than 30.8% (2x of 15.4%). Since the projected increase will only be 25%, it is suggested to add a single
member of staff.
One possible reason that the efficiency does not increase linearly with the staff count is saturation of
the work space. Beyond a certain number, no addition of further staff will lead to any increase in
productivity of the department. While this actual number is unknown, it is believed that seven members
of staff (5 original + 2 additions) would be approaching saturation. This would explain the gradual
decrease in efficiency rise.
Upon the addition of this new member of staff, this study should be redone in no less than 15 months (3
months to allow for training, and 12 months to allow for optimal performance). Then, a similar study will
reveal if there is a need for an additional spray booth.
3. Economic Analysis
A simple economic analysis was conducted. The first step was to review the costing of part
repair/changes for the years 2012-2014.
Table 11: Spray Booth Part Replacement Cost
Year 2012 2013 2014
Total Part Replacement Cost (RM)
2774.8 12050 14685
Increase from Previous Year (%)
N/A 334.3 21.9
From this table, it is shown that the amount being spent on part replacement is increasing yearly. There
was a three-fold increase from 2012-2013 and this coincides with increasing usage of the spray booth. A
greater usage will lead to greater wear and tear, and consequently higher repair fees. It is predicted that
the costing (and usage) will increase by 15% for 2015, and a further 20% for 2016.
Table12: Forecasted Increase in Repair Costs
Year 2014 2015 2016
Total Part Replacement Cost (RM)
14685 16887.8 20265.4
Increase from Previous Year (%)
21.9 15 20
The above values do not incorporate the annual servicing fee, which is a contract signed every
December. The servicing fee for 2014 and 2015 are shown below, together with the forecasted fee for
2016.
Table13: Annual Servicing Fee
Year 2014 2015 2016
Total Annual Servicing Fee (RM)
12600 12600 12600
Number of Services 6 6 6
In addition to that, a new spray booth will also require additional utilities (electricity). The total electrical
cost (with the inclusion of GST) for the factory for the months of May, June and July 2015 were
summarised in following table;
Forecasted Values
Table14: Electrical Bill for May-July 2015
This figure represents the electrical cost for the offices, the machining department, the Special
Processes Division and the Quality Control centers. As such, it was approximated that the paint
department (spray chamber) used about 10% of the total electrical consumption.
Justification
The spray booth has 4 main sources of power; lights, suction fan, air conditioning system and an air
pump. The fan, lights and air conditioners are switched on 24 hours a day, while the air pump is only
used when parts are being sprayed. Hence, it was jointly assumed that the spray booth would account
for 10% of the total electrical consumption.
10% of 1,412,687 KWh/KW = 141,268.7 KWh/KW.
Hence, the electrical bill for the spray booth for May-July = 10% of Rm568,563.9
= Rm56,856.4 over that period.
Assuming uniform usage over the year, the total electrical cost for the spray chamber
= Rm56,856.4 x 4
= Rm227425.6
Hence, we will make an assumption that the total electrical cost for a new spray booth for the year 2016
= Rm22745.6
Additional charges for environmental inspection will be Rm900 per year.
Month
Electrical Power (KWh/KW)
Cost (RM)
May 460,916 186,612.7
June 461,798 186,839.5
July 489,973 195,111.8
1,412,687 568,563.9
In total, the expected annual operational costs for 2016-2018, for a new spray booth, are shown below;
Table15: Expected Operational Costs for 2016-2018
Year 2016 2017 2018
Total Operational Costs (RM)
56,511 58,206
59,952
Hence, with an expected capital cost of Rm1.2mil, the total expenditure on an additional spray booth
from 2016-2020
= 1.2mil + 56,511 + 58,206 + 59,952 + 61751 + 63604 =Rm1.5 mil
Table17: Total Working Time and Sales
Year 2013 2014 2015 2016 2017
Total Working Time (Hours)
409278 711074 809342
971210.4
1116892
Increase from previous year (%)
N/A 174 114 120 115
Total Sales (mil RM)
68 75 85 110 150
Increase from previous year (%)
N/A 9.3 11.8 29.4 36.4
Average Sales per Unit Time (Rm/Hr)
166.1 105.5 105 113.3 134.3
From the calculations in tables 2&3, it can be found that the amount of time that can be saved per day
shift by the addition of a new spray booth averages out to 75 minutes (= 1.25 hours)
Values extrapolated from
existing data and forecasts
Assuming that the night shift shares the same efficiency, total daily time saved = 2.5 hours.
Over 365 days, total hours saved = 913 hours
Based on the average value of one working hour for the years 2016-2020, the total value gained over
one year for a new spray booth
= 913 hours saved x Rm135/hour
= Rm 123255
And hence, over 5 years
= Rm 123255 x 5
= Rm 616275
Return of Investment
= 616275/1.5mil
= 41.1%
Addition of new staff
Based on the values calculated in table 17, it was found out that 1 working hour averages out to Rm135
earned in sales.
Based on table 10, an additional staff will reduce the part mart masking time by 0.4 minutes each. If the
daily average number of parts is 162 (tables 7&4), the total time saved in a day
= 162 x 0.4
= 64.8 minutes.
In a year
= 23652 minutes
In 5 years
= 118260 minutes
= 1971 hours
= Rm 266085 saved
Assuming that a factory worker’s average monthly salary over 5 years is Rm2500 (the actual figure
wasn’t given to me), the R.O.I
= 266085/150000
= 177%
Assuming no other changes
elsewhere, payback period for new
spray chamber (based on method of
calculation) = 12.5 years
Discussion
The various tables and calculations in the previous pages display 3 important pieces of information:
1) The efficiency of the existing spray booth (45%)
2) The potential increase in masking efficiency with additional staff (15.4%)
3) The predicted expenditure to construct and maintain a new spray booth (Rm1.5mil)
Based on all this information, there are several conclusions that we can draw;
1. There is insufficient need to construct a new spray booth
The calculations show that the actual usage of the current spray booth is only 34%. This means that it is
only used one-third of the time. An additional spray booth will not increase the usage, but in fact cause
a division in usage to further reduce the efficiency.
Recommendation: Do not build a new spray booth
2. The part masking department is under-staffed
On average, a single part will take 2.6 minutes to mask. This value can be reduced by 15.4% with an
additional staff, to 2.3 minutes. A higher masking rate will directly lead to a higher painting rate, and
greater usage of the spray booth. An additional staff investment will have a R.O.I of 177%
Recommendation: Commission a new staff to join the paint masking team
3. R.O.I for new spray machine = 41% over 5 years.
Utilities, maintenance, repair and construction costs, along with a growth rate of 3% were factored into
this calculation. Since, the economics do not add up, and the need is not there, there is no need to build
a new spray machine
Recommendation: Do not build a new spray machine