lean manufacturing

LEAN MANUFACTURING 1


Lean Manufacturing Principles and Techniques

Presented by:-

Eng. Mohammed Hamed Ahmed Soliman

Content:

1. Lean Manufacturing Principles

2. Productivity Measurement, Analysis and Improvement

3. Effect & Elimination of the Manufacturing 7-Wastes

4. Lean Improvement Techniques

5. Lean Management for Making Improvement & Gaining Sustainability


TOYOTA BUSINESS 5

Overview on the Toyota Performance & Business Success

Toyota’s annual profit at the end of its fisical year in March 2003 , was 8.13$ Billion-larger than the combined earnings of Chrysler, GM, and Ford.

Toyota has a profit margin of 8.3 times higher than the industry average.

While the stock prices of the big three was falling in 2003, Toyota’s shares had increased 24% over 2002. Toyota’s market capitalization was 105$ Billion as of 2003.

The return on asset is 8 times higher than the industry average.

TOYOTA BUSINESS 6

The company has made a profit every year over the last 25 years and has 20$-30$ billion in its cash war chest on a consistent basis.

Toyota has for decades been the number one automaker in Japan and distance fourth behind the big 3 automakers in North America. But in AUG 03, for the first time, Toyota sold in North America more than one of the 3 big automakers (Chrysler).

In 2003, Toyota was on track to sell more vehicles in the US than either of the two brand names that have led US sales for the past 100 years—Ford and Chevrolet. Camry was top-selling US passenger car in 2003. Corolla was the top-selling small car in the world.

Toyota became the leader in producing luxury cars when they introduced the Lexus firstly in 1989.

Toyota invented the lean production, known inside Toyota as TPS Toyota production system.

TOYOTA BUSINESS 7

Toyota has the fastest product development process in the world. New cars and trucks take 12 months or less to design, while companies require typically 2 or 3 years.

Toyota automobiles have been consistently been at the top of quality rankings by JD Powers and Associates, Consumer Reports, and others for many years.

In the small cars category (Toyota Corolla, Ford Focus/Escort, Crysler Neo, GM Cavalier), Toyota won each of the last three years for overall reliability, as well as the prior three years, and predicted reliability for 2003 model year.

For family sedans, the Toyota Camry beat out the Ford Taurus, the GM Malibu, and Dodge Intrepid, wining in the last three years, the three prior years, and predicited reliability for the 2003 model year.

More than half of all Toyota used cars are singled out as “recommendedfor purchase,” compared with less than 10% of the fords, 5 percent of the GMs, and none of the Chryslers.

TOYOTA BUSINESS 8

Toyota Lexus has dominated the J.D Powers “initial quality” and long-term durability rankings for years. Toyota Lexus was again the #1 most reliable car, according to the J.D. Powers 2003 quality survey, Followed by Prosche, BMW, and Honda.

Toyota’s Profit in 2014 was around 18-19$ Billion

Lean Principles


The five principles of lean

Lean has some goals, intentionally looking from the perspective of the customer. The five principles of lean are defined below:

1. Value: Specify what adds value to the customer and what doesn’t. Customer needs a good quality, good prices and good delivery speed. Quality should meet the customer expectation, no exception. Non values added processes are those that customers are not willing to pay for. They add cost to the product and delay the manufacturing process.

2. Value stream: This involves every step of the process starting from the supplier and ending with the customer. Every step must bring the product closer to the completion and add value to it.


3. Make the product flow: All obstacles that are constraining the flow of the parts through the manufacturing processes must be removed. Lean strive for one piece flow, which is about providing smooth flow for each piece of product with no wastes in time, performance, and quality, in order to deliver the product quickly to the customer.

4. Pull not push: Producing what the customer needs, and avoid over productivity that creates the most of ever wastes in the production processes.

5. Strive for perfection: There must be a vision for perfection. Companies should strive to continuously improve the process rather than being good at what they are doing.The seven-wastes are those non-value added steps that obstacle the flow of the stream, add cost to the product, reduce quality, and delay the process.


Non-Value Added & Value-Added

Value is something that adds to the process or to the customer. Value added is good, non-value added is bad. Value actually is what customer want to pay for.

Value stream. This present every step from the start to the end of the process. Every step of the process should bring the product closer to the completion.

Add value What adds value to the customer which customer is willing to pay for.

Non-add value essential Activities that support the process. Will need to be minimized.Ex. The maintenance, quality check points, changeovers..etc.

Unnecessary non-add value Ex. The seven wastes. This need to be completely eliminated.


TOYOTA BUSINESS 13

7 Wastes:Commonly known in lean language as Muda “which is a Japanese term”.It has been given a shortcut as “TIMWOOD”

T=Transportation, I=Inventory, M=Motion, W=Waiting, O=Over processing, O=Over

productivity, D=Defects.

ASFOUR TRAINING SESSION 14

For example, if there is a manufacturing process consist of several processes such as cutting, casting, assembly, handling, maintenance, inspection, and changeovers. The added value works which involve making what the customer needs is just a few processes which are cutting, casting, and assembly.

The others are those non-value added works that need to be removed or minimized. The seven wastes define those non-value added in terms of transportation, inventory, motion, waiting, over processing, over productivity, and defect. They have been given the abbreviation Timwood. The 8th waste is the underutilization of human capabilities or untapped human potential.


Cutting process

Lathe Process

Changeover Maintenance Downtime

Machine SettingRe Work Absent

Wait for Tools

TransportationValue Added

Non-Value Added

Weld Drill

Flow Flow Flow

Main goal is to reduce the Lead Time & increase productivity rate per hour

Assembly


Takt Time

One of the most important calculations in lean is the takt time, which is the rate of customer demand for group or family of products produced by one process.

Takt time is calculated by dividing the effective operating time of a process (for example per shift or per day) by the quantity of items customers require from a process in that time period.


𝒕𝒂𝒌𝒕 𝒕𝒊𝒎𝒆 =𝒚𝒐𝒖𝒓 𝒆𝒇𝒇𝒆𝒄𝒕𝒊𝒗𝒆 𝒐𝒑𝒆𝒓𝒂𝒕𝒊𝒏𝒈 𝒕𝒊𝒎𝒆 𝒑𝒆𝒓 𝒔𝒉𝒊𝒇𝒕

(quantity customer require per shift)


Example. Takt time calculationsThe effective operating time for a process is 25,200 seconds per shift.

The effective operating time = operating time-allowances

Allowances such as planned downtime, lunches, breaks, team meeting, cleanup, and planned maintenance.

The changeovers, unplanned downtimes are those variables that need to be improved to have the best effective operating time.

Customer demand rate= 420 pieces in a shift

Takt time= 25200/ 420= 60 seconds

Based on the available time, on average the customer is currently buying one unit every 60 seconds.


The actual intended cycle time of an assembly process, called planned cycle time, is usually less (faster) than the takt time. In less than one hour, we expect this machine to produce 60 pieces of product. Any interference would reduce the productivity rates of this machine, and delay the product for the customer.

Seconds

10

20

30

40

6050

Process Output Cycles

An unstable process


The OEE could present those interferences in terms of availability, performance, and quality.

Many of us track pieces produced per hour or shift and therefore unable to answer the question “at how many seconds per piece should this process be cycling?”


OEE Overall Equipment Efficiency

Overall equipment efficiency (OEE) is a total productive maintenance (TPM) module; machine capacity is a part of all three terms: availability, performance, and quality. Each term present numerous improvement opportunities.


How OEE is related to productivity and capacity?

OEE measures the ratio (%) of what product is actually made which is defect less and sellable, to what could be made according to the design. One hundred percent of OEE is the design or maximum capacity a process or a machine is designed to make with zero defects.

The intention is to find why this process is not working as what have been expected, and why the real output is low. Then, some actions should be taken to maximize the current process capabilities, fix problems, and improve productivity.

Why use OEE & what is the intention behind this?

𝑹𝒆𝒂𝒍 𝑫𝒆𝒇𝒆𝒄𝒕𝒍𝒆𝒔𝒔 𝑶𝒖𝒕𝒑𝒖𝒕 / Design Output


OEE Metrics

OEE involves three metrics, described as follow:

1. Availabilitythis is a time metric that is usually measures as a percentage of the operating time. Machine availability is a measure of how much time this machine was available to run product. A machine that is busy or can’t make product is considered unavailable.

Improving the machine available time by reducing wastes and excess motions from the process will improve:

Costs Utilization of both operating time & resources Time required to make a product Overtimes


2. Performance: This is one of the most debate issues. It takes into account the factors that are affecting the speed of the machines. Most of companies take the number of pieces produced and compare it to the design, count quality and availability, then, assume the problem is a machine speed that has been caused by in proper maintenance.

Actually, the performance can be affected by many other factors:

1. Untrained operators

2. Bad/insufficient operation instructions

3. No instructions


What is the effect of working at lower performance or speed?

Consume more resources

Waste money

Longer production lead time

More operators

Some companies plan their productivity according to the current situation and the current process capability, making a few hours job last the whole shift. With no trial to evaluate the process or see if it can be improved, the process will never run efficient.


3. Quality This is one of the greatest wastes in the process. Quality is so important for customers, adding value to your customer is what keeps you in business. If a process is producing a number of defected pieces, the required working time to compensate those defects and re produce sellable items will reduce the capacity of making a new product and will consume more resources. Cost of producing a defected piece plus the cost of re working it could be more than double the cost of making it right at the first time. And if a defected product passed to the customer, this can lead to complete business loss. It is more important to make sellable parts rather than focus on just making high number of parts. Reducing the defects ratio will improve the real output of the machine, increase the capacity of making product, reduce the inspection effort, reduce costs, and add value to your business.

Quality Cost

Defect Parts

Re Work Parts


Find: What waste time? What slow the speed? What degrades the quality?

Production availability & time analysis

As shown in fig.1, availability of the machine can be affected by any of these factors. Each problem in fig1 presents a different type of improvement. Availability often presents the waiting waste which is one of the most common wastes in terms of muda (seven-wastes). It can be seen in the most of process improvement events.

Unfortunately, many people use the availability as a measure of uptime subtracting many other wastes, and present the formula by this way:

𝑻𝒐𝒕𝒂𝒍 𝒘𝒐𝒓𝒌𝒊𝒏𝒈 𝒕𝒊𝒎𝒆 (𝒖𝒑𝒕𝒊𝒎𝒆 + 𝒅𝒐𝒘𝒏𝒕𝒊𝒎𝒆) − 𝑻𝒐𝒕𝒂𝒍 𝒅𝒐𝒘𝒏𝒕𝒊𝒎𝒆

𝑻𝒐𝒕𝒂𝒍 𝒘𝒐𝒓𝒌𝒊𝒏𝒈 𝒕𝒊𝒎𝒆


The above formula tends to focus on an individual process which is the machine downtime, often caused by preventive maintenance, routines, adjusting, calibration, overhaul and the other maintenance activities.

The maintenance folk’s main goal is the uptime-keep the equipment working which does not means that this equipment is available to run product. There are still many factors influence the availability of the process or machine as presented in fig.1. But by considering only downtime, this means reducing the PM time or the mean time to repair (MTTR) and losing the opportunity to improve the overall process effectiveness. The main goal of the OEE is to understand the obstacles and wastes that are lowering the productivity rate. For this reason, the availability should be presented by this formula:

𝑇𝑜𝑡𝑎𝑙 𝑝𝑟𝑜𝑑𝑢𝑐𝑡𝑖𝑜𝑛 𝑤𝑜𝑟𝑘𝑖𝑛𝑔 𝑡𝑖𝑚𝑒 − 𝑇𝑜𝑡𝑎𝑙 𝑝𝑟𝑜𝑑𝑢𝑐𝑡𝑖𝑜𝑛 𝑑𝑜𝑤𝑛𝑡𝑖𝑚𝑒

𝑇𝑜𝑡𝑎𝑙 𝑝𝑟𝑜𝑑𝑢𝑐𝑡𝑖𝑜𝑛 𝑤𝑜𝑟𝑘𝑖𝑛𝑔 𝑡𝑖𝑚𝑒


Productivity time

Non-Value AddActivities

Wait for loading

Machines setting time for changeovers

No operators

Break-times

Operation Losses Value-add

Figure 1. Most common availability and time lost issues during the operating time

Maintenance downs

Wait to get tools

Wait for quality inspection

Wait for CNC program loading

Wait for instructions

Wait for materials

Wait for spare parts

Electric cut-off

Wait for the manufacture

drawing LEAN MANUFACTURING 31

Performance Analysis

In many times, the primary cause of performance issues is hidden and overlap with the availability metric.

Performance

Maintenance issues

Data Management programs like ERPs don’t provide solution or root cause of the problem.

The reason of low machine output

regardless of the quality issue and availability can

be the speed of the machine

Operator Skills

Training Skills


It is hard to catch the performance reasons by a software. It will require a deep observation at the gemba.


Quality AnalysisIt is not difficult to know how many defects exist using a simple sheet to record the number of the defected parts which can’t be sold. What is not easy to know is the cause of this defect which requires an intensive effort to understand the source of variation that is causing the quality problem. It will be necessary to perform an in deep process analysis in order to grasp the real situation for elimination of the root causes.

Toyota way of analyzing & solving quality problems :

1. Genchi genbutsu (Observe the real situation at the gemba)

2. Mistake-proofing (Poka Yoka)

3. Simple tool like Pareto for data analysis

4. Ask 5 whys to find the root causes.

What Six Sigma and other complex analysis tools can do?


Code Equip description Downtime hrs

(average)

frequency Percentage

A1 Product Changeover 5 4 12.50%

A2 Maintenance downtimes 4 6 10.00%

A3 Bringing tools 4 2 10%

A4 Waiting for material 3 2 7.50%

A5 Quality check 2.5 1 6.25%

A6 Preventive maintenance 2.5 1 6%

A7 Wait for instructions 1 1 3%

A8 Electric current problems 0.5 1 1.25%

A9 Others 0.2 1 0.50%

A10 ---- ---- ----

Data Analysis & Priority Identification

Production downtime weekly report.

Total Operating time= 40 hours


Equipment

Code

Equip

description

Downtime hrs

(average)

frequency Percentage

K1920 Cutting 7 4 17.5%

K1921 Skimming 5 6 12.5%

K1922Attachment 4

47.5%

K1923Forming 3

310%

K1924Assembly 3.7

29.25%

Production Downtime Analysis by Eq


Pareto Analysis A problem solving tool that breaks data down into manageable groups and identifies the greatest opportunity for return on investment. The analysis is based on the Pareto Principle, also known as the 80:20 Rule. Simply stated, the principle says that 20% of a population will cause 80% of the problems associated with the population

0.00%

2.00%

4.00%

6.00%

8.00%

10.00%

12.00%

14.00%

0

1

2

3

4

5

6


How to set priorities for Improvement Start?

Which machine or line to begin with? A famous question that is being discarded in every improvement debate is which process to start analyzing first and calculate OEE for? Which production line? Or which machine?

There is a recommendation to start analyzing the pacemaker process. In the automotive industry, pacemaker is the assembly process; this process is connected to various external customers and can affect the customers directly.


Which problem to start with?

After reviewing the metrics details, the next question become which problem to work on to understand it better with “go and see” approach and improve it? Pareto analysis is a good answer. Process can be analyzed and each factor influenced the efficiency of the process is given a weight depending on its greatest effect in terms of money. However, it is not always the best to start with the biggest problem that poses the great cost.

Pareto may not work if the situation at the process changed, this will lead to something called Pareto paralysis. This is something that should be avoided, and people can spend long time searching for the right first step to take!


Actually, defining where to start may depend on the current culture driven by the company. For example, if managers and directors are resisting the improvement, then it is better to start with the one that can be fixed quickly and easily to present the benefits from the process improvement, and get the support as needed from the top management for continuously improving the other processes.


Gemba or genchi genbutsu


Go and See to observe the real situation.

A place where the value creating works happen.

A place where real problems solving should be carried.

A place for developing leaders.

A place where the improvement is carried.

A place where hidden problems exist.

What is Gemba?



Grasp the real situation at the Gemba


Benchmarking is a tool for quality analysis and

improvement

1st TransportationTransportation is about material handling. It involves all material movements from the supplier to the customer. What creates most of wastes in the manufacturing process is the movement of the parts through the production processes. It adds more cost on the product, and could affect external customers directly, causing a delay in orders delivery.


Factors affecting the transportation efficiency

The layout of the plant.

Distance between the different manufacturing process steps

Distance between machines inside each workstation

How close are the workstations and machines to the tools

How far are the inventory warehouses from the production facilities

How far are the other service departments such as the maintenance

workshops from the production lines.


Considerations to minimize transportation:

Mistakenly, many manufacturers tend to arrange machines by similarity rather than by the sequence of the process steps. For example, if there are two processes, cutting and skimming, and a process of heat treatment that is required between both, then, the oven should be placed between the cutting machine and the skimming machine. Long distance between the process steps increases the time it takes to produce one piece of product and more resources will be needed to move one product from a process to another.


Machines arrangement should take into consideration the following things:

Minimizing the work in process WIP inventory

Minimizing the time it takes to produce one piece of product

Be faster than the takt time which is the customer demand rate for a product or group of products.

Consider all workstations, machines, and operation tools to be as close as possible to avoid waiting for tools or parts issue and what is called ergonomics in the workplace.


Cost effects of transportation:

Cost of the transportation equipment like forklifts.

Cost of operators driving forklifts

Safety risks due to using forklifts in the area

Labor wages,

Cost of resources

The risk of product deterioration during the handling process

The effect of delays on the customer.


Cost Benefit Analysis Involve in Decision Making

A common thinking that the transportation problems has no solution if the root cause came up to a point where the company must re arrange machines and processes to be closer. This action is considered very costly, so many companies won’t even think about it. This is not exactly correct, as long as the main goal is to have an efficient process with minimum wastes and shortest lead time for long-term benefit. Such wastes could affect any organization financially on both long and short terms. Also, this may affect the external customers too, and customers satisfaction worth more than money. If a cost benefit analysis is carried to determine whether to re arrange the process steps by sequence or keep them as they are, the accumulative cost of keeping the current condition over weeks, months, and years could be much higher than the cost of doing the job once and forever. So, this is the key point. The cost of losses must be estimated over months and years. Also, when the company decides to make the changeover, this can be performed gradually.


Toyota way of thinking about cost-benefit analysis

They believe that management decisions should be based on long-term improvement that matches the company’s vision and goals. And As long as this improvement is in the company’s vision, cost benefit analysis is only being carried to determine the best method to make the improvement not to decide whether to make it or not.

Toyota principle: Base you management decisions on long term financial improvement even at the

expense of the short-term benefit


2nd Inventory

This is one of the greatest wastes. Inventory issues are greatly affected by the production system. But the improper sales forecasting, and the bad procurement planning are also reasons for inventory problems.Reducing the inventory storing value became the main goal of any industrial company. The just in time JIT theory and approaches like Kanban have been utilized to serve the manufacturers demands in reducing the inventories, and keep some buffer for emergencies.


The high inventory turns became an indication of how this organization is profitable. You want to spend money on materials and quickly get the return by selling the finished goods. The total selling revenue recover profits, and other costs such as indirect salaries, direct salaries, plant expenses, manufacturing overheads, depreciation, taxes, and insurance.

𝑰𝒏𝒗𝒆𝒏𝒕𝒐𝒓𝒚 𝑻𝒖𝒓𝒏𝒔 𝑹𝒂𝒕𝒊𝒐 =

𝑻𝒐𝒕𝒂𝒍 𝑨𝒏𝒖𝒂𝒍 𝑷𝒓𝒐𝒅𝒖𝒄𝒕 𝑺𝒐𝒍𝒅

𝑨𝒗𝒆𝒓𝒂𝒈𝒆 𝑰𝒏𝒗𝒆𝒏𝒕𝒐𝒓𝒚 𝒊𝒏 𝑺𝒕𝒐𝒄𝒌(𝒓𝒂𝒘𝒎𝒂𝒕𝒆𝒓𝒊𝒂𝒍 +𝑾𝑰𝑷 + 𝑭𝒊𝒏𝒊𝒔𝒉𝒆𝒅 𝑮𝒐𝒐𝒅𝒔

Inventory types are the raw material inventory, the work in process WIP inventory, and the finished product inventory.



E.g. if the cost of goods sold in the period was 1000 and the inventory was 100, then the ITO was 1000/100 = 10 times. The ITO can as well be expressed as throughput time (TPT). If the ITO is expressed as times a year, then the TPT is calculated as 365/ITO days. In the example the TPT would be 365/10 = 36.5 days. To measure the ITO for a single item, you can simply calculate units sold/units in inventory.

Trim Master, Inc (seats supplier) for Toyota Motor Kentucky has a ITR of 135times per month!

Cost effects of inventory: The direct cost of the inventory carrying can be estimated through the following parameters:

1. Return on investment ROI:Any investment should have a return. The quicker you get this return, and the better it will be. If money has been spent to buy some materials needed for the production process, a quick return is good; a delay in selling the finished product to the customer is bad. The idea is that this investment amount could have been spent on something else, or putted in the bank. Delay in getting the return involves the interest losses during this period, and what is called opportunity cost. This money could have been invested in another profitable opportunity or project rather than being wasted on some sluggish materials.


2. Risk:The risk of parts deterioration and damage varies. It depends on the product type. If this product has an expiration date like food, or glue, then it will be very risky to store them. Therefore, most of fast moving consumer goods FMCG companies try to accelerate the inventory movement and keep as minimum value as possible in their warehouses.Furthermore, stocking too much inventories, put the business on risk if there was a market change like change in the raw material prices or in the currency value. There is also the risk of accidents such as fires.At the same time, having no inventory, puts the business in another risk, if the supplier has went down unexpectedly due to economic problem or a nature disaster like the earth quakes in Japan, and tsunami.



Toyota are best and the leader of inventory management. They stock parts from more than one supplier, indeed two suppliers for each part type. When the tsunami and japan quake occurred, some suppliers went down, but Toyota has taken numerous actions to rectify the issues quickly.

3. Material handling:This is the cost of transporting goods. Some accountants see stocking the inventory one time per year is economically good from the cost of transporting view, but actually this puts the whole business in risk and affect the profitability of the company.

4. Space:Inventory takes much space and requires additional space renting or buying. The space is valuable whether this space is rented or owned by the manufacturer. The company may found itself has to re buy more spaces for more production lines to expand their business, while there is a lot of inventory taking much space in the factory. It is better to minimize the inventory rather than buying more spaces to store it. Either, those additional spaces will need more resources such as a ventilation system, manpower, equipment, energy, and data recording system.


5. Insurance and taxes: Spaces need insurance, as well as the insurance for all transportation equipment and the manpower. Also taxes are applied in some areas on the inventory.It is clear that higher inventory turns is a good sight, low turns is an indication of lazy system and unprofitable one.

An example of the inventory turns ratio at one of the Toyota suppliers. In 1994, Toyota set up Trim Master, Inc TMI as a joint venture plant to supply seats for the opening of its new plant in Georgetown, Kentucky. The TMI had an inventory turns of 135 turns per month! This has been reported by Jeff in his bestselling book Toyota Way. The author thought that he has caught an error and the number of turns is per year, but it was really per month!

Carrying cost in industrial companies is 25-55% from the total inventory amount


WIP Inventory Hidden Costs:

Hides many issues behind it

Problems are not visible

Increase waiting between the process steps

Increase lead times

Root cause finding of quality problems is difficult

More wastes

Delay in customer delivery


Rocks signify quality, downtimes, and other production problems


Considerations to minimize inventory

Production style affect the inventory. Pull or Push?

Building too much work in process WIP inventory between the process steps or using a production system based on large batches, will constraint the parts flow through the manufacturing processes. A process might have to wait for parts that need to be made until they are all finished with the other process that supplies it.

The main lean goal is to make one piece flow through the production processes, and minimize the work in process WIP inventories. Producing small batches is also a good idea, and will help facilitate the transportation without using heavy equipment like forklifts. Trolley and other light equipment are preferable for both cost and safety issues.


The main lean goal is to make one piece flow through the production processes, and minimize the work in process WIP inventories. Producing small batches is also a good idea, and will help facilitate the transportation without using heavy equipment like forklifts. Trolley and other light equipment are preferable for both cost and safety issues.

Minimum Wastes

Maximum Delivery Speed

Minimum WIP Inventory

Shortest Lead Times


Should we have zero WIP inventory?

At the same time, having zero WIP inventory will put the process in risk of stoppage if another process is supplying it with parts has been went down unexpectedly. Using an inventory buffering system is a good idea to avoid emergencies. Materials or parts can still be pulled to the production lines but with a little bit of safety stock using a technique like Kanban to provide the needed materials on time and with the right quantity.


3rd MotionThis is the ergonomics. The operator needs to have his tools and parts handed to him in exactly the right orientation to eliminate wasted walking and handling losses.

5S is a good technique to eliminate the operator searching for tools issue. By ensuring there are enough tools available in place, and give them a location so they are being returned after use. By arranging the tools and putting them in a clear place, access to the tools became much easier now. Shadow boards would be helpful to realize if a tool is missed. Basically the tools are outlined and a missing tool show a shadow when it is not there. The board should be followed up regularly to ensure tools are returned after use.


Tools should be returned after use

Someone should follow up the board regularly to ensure tools are available, in good condition, and returned after use.

Each tool should be outlined on the board, if one is missed, it will be recognized.


4th Waiting

This is the time waste factor, and it involves the following activities:

• Waiting for materials.

• Waiting for spare parts.

• Waiting for the quality

inspection process.

• Waiting for services such as waiting for maintenance crafts

• Waiting for quality inspectors.

• Low machine performance/speed.


When calculating the takt time, and customer demand rate, those are the variables than need to be eliminated to improve the effective operating time.

• Waiting due to machine downtime, repairs, and preventive

maintenance.

• Waiting for operators to get tools or spare parts.

• Waiting for changeovers from one product to another.

• Waiting for CNC machine loading program.

• Waiting for instructions or design drawing.


Over productivity and inventory issues are related. Over productivity creates most of production wastes. Making product more than what is actually needed or over the capacity of the selling department is a waste of money in enormous rates. The losses are the costs that have been spent to make this product. Even if this product is going to be sold later, there is still a problem with the return on investment for the raw materials and the other resources that have been used to make this product.

Pulling product to customer is one of the main lean goals. And if the product is computer or a modern technology, so the company will be in troubles. Technology changes fast, and cannot be stored for a period of time.

5th Over productivity


In additional, for any goods that have an expiration limitation date, producing with mass of quantities with no realization of where this product is going to be sold, put them in danger of damage and deterioration. The goal is to make only what is needed and when needed. A method like Kanban can be used either with the finished goods to produce according to the customer demand.

Basic Kanban or Pull System mechanism

Kanban (pull system)


1. The customer process (assembly process as shown in the fig) receives some form of production instruction.

2. The material handler serving this assembly process regularly goes to the up stream store and withdraw parts that the assembly process needs in order to fulfill the production instructions

3. The supplier process then produce to replenish what was withdraw from the supplier store.

Kanban is an inventory buffer, and a production regulation tool.


The same machine

The same machine

What parts run on what machine?


PatternFlexible

• Can run any part on any process

• Many variables

• Difficult to understand causes of problems

• Strives to dedicated part numbers to processes

• Easier to understand causes of problems


Cost effects of over productivity: Over productivity create the most of manufacturing wastes.

Mass productivity holds many downtime problems

Mass productivity holds many quality issues behind it.

Increase the non-value added

Longer lead time of making product

Delay in delivery to customer

Waste of money

Producing one piece or small batches will help pointing out the production obstacles quickly and discover the root causes before problems are developed.


Traditional Mass Productivity Thinking VS Lean Thinking

One of the most debate issues is the use of mass production technique. The approach involves making as many parts as possible using the maximum available resources and all available machines. It doesn’t take into consideration the customer demand rate or the sales forecasting.

Furthermore, if you are making 500 parts, and there were a problem with the production process, a quality failure can occur with all of those parts. Problems are hidden with the mass productivity approach; it will be also so difficult to discover where the error is coming from. So the root causes will remain hidden.


If a supplier process is producing with mass productivity and building too much work in process WIP inventory, the downstream process will find all what it needs even if the supplier process has been went down suddenly. The downtime is hidden, and is not important; no one will consider preventing it in the future unless it has an obvious affection on the production process. Also if the operator at the supplier process is spending time getting tools or parts, the downstream process is still receiving the parts it needs to make.

Mass productivity creates the inventory problems, hides many wastes behind it, and effect the delivery time to customers. If you are assembling one piece of product in 3 minutes, waiting for 10 pieces to be assembled will take 30 minutes. The cycle time of one piece became 30 minutes although the add value time is only 3 minutes.


Large batch processing


Continuous product flow


With pull concept, and producing only what is needed for each process step and between the production lines, there will be a minimum work in process WIP inventory. If a process is went down, the downstream process won’t be able to receive parts, and the upstream process won’t be able to produce and build WIP inventory. Problems are now surface and clear. And everyone will strive to fix downtime and prevent the recurrence of this downtime.



Advantages of pull system:

Problems are surfaced quickly

Produce according to the customer needs saving cost & resources

Reduce the WIP inventory

Shorter lead time

Increase value-added work

Better quality control

CT=104 min CT=76 min CT=104 min CT=40 min

CT=40 min

Assembly

SawLatheDrillWeld

0.75 daysWIP

0.25 daysWIP

1.7 daysWIP

0.13 daysWIP

Lead times=3.75 days

CT=Cycle TimeWIP=Work In-Process


CT=105 minCT=103 min

CT=108 min

Weld

0.13 daysWIP InventoryMin= 0Max= 1

Lead times=0.80 days

Saw, Lathe, Drill

Assembly

0.13 daysWIP Inventory

Min= 0Max= 1


Before After

Production Lead Time 3.75 days 0.8 days

# of forklifts 11 1

Travel Distance per product piece

1700 ft. 1000 ft.

Result of Lean Transformation


6th Over processingIt means making more steps in the process than what are actually needed or making steps that are not needed. By asking some questions while mapping the process, we can allocate the over processing:

• Why do we do this step? Is this step needed?

• Why do we do it now?

• Why do we do it this way? Is there an easier way to do it?

• Do we need this step?

• Can we eliminate this step? Or reduce its time?

• Can we do two steps together at the same time? Can the step be

grouped with others and preassembled?

• Could two tasks be done at the same time?

• Would two peoples doing the job make it faster?


Many processes can be improved and reduced time through removal of the unnecessary steps. The improvement is not only limited to the manufacturing process itself, but also to the other processes such as changeover, maintenance, and material movement. The most common reason of why over processing is exist, is the work standardization. No standardization creates many wastes.

Standardization is a good way to avoid over processing, mistakes, defects, and other wastes.


TOYOTA BUSINESS 88

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Mapping as a lean tool for process improvement


What is Mapping? it is a range of techniques for analyzing the steps (or stages) in process. Any process is suitable. As experience, the most common maps are in processes-the way a product is manufactured.

Why Mapping?Mapping is used most often to analyze a process to find ways to improve how the task is carried out. If lean principles are applied, we can make any process more efficient.

With a team skilled operators and engineers, we can identify any steps where errors are introduced and where they effect the rest of the process.


Is Lean a Positive or Just an Extra Work?

The company/Managers/Engineers need to decide carefully whether to spend their cash on a promise of something better or a bit of equipment that will do something better.

It is pretty much guaranteed that unless the improvements are embedded in the daily life and the culture of organization, they will evaporate away.

For prolong success, the improvement work never must be regarded as extra work. It needs to be ongoing like the preventive maintenance program or the scheduled program.


•Basic Process Mapping•The Big Picture Map•Capacity Maps•Value Stream Mapping ”VSM”•Value and Capacity Stream Map•Swim Lanes Mapping.•SIPOC Maps.

Commonly used for:-As a tool for problems finding and process improvement.

-Pointing out inefficient process steps “non-value added”.

-Allocate wastes and remove them.

Mapping Tools:

Process mapping is a workflow diagram to bring forth a clearer understanding of a process or series of parallel processes.


•Value Stream Maps.The non value added and the value added are being separated in the map, time of each is calculated and pointed out, so the time saving by eliminating the non-value is clear.

Value add

Non-value add

Value add Value add Value add

Non-value add Non-value add

•Process Maps.Look for all details inside each dept, point out the wastes and improvement chances, , its the most common map.

This is my preferred MAP, and will begin with it. Other maps can be discussed in the next report.

Process MAP can zoom ++ for specific points and show up the wastes in wider scale.


Toyota Production Goals

Zero Defects

100 percent value added

One-Piece Flow, in sequence, on demand

Security for people



Phase#1 Preparation for the Kaizen Event

1. Clearly define the scope of work

2. Set the objectives: like improve quality, reduce costs, reduce lead times…etc.

3. Create preliminary current state map

4. Collect all relevant documents and data

5. Post the preliminary current state map on the wall in a room

Define the Customer Requirements

Current State Map

Future State Map

Implementation Plan

Do it

Evaluate

-Scope of Business-What is the value add to customer?-Measurable objectives

-Process steps-Process flow-Point out non-value added & value added

-Eliminate non-value added-Kaizen work

-What? Who? When?-Communication and Training Plan

-Begin workshop

-Establish process metrics-Visually track progress-Continuous Improvement

Data

Kai

zen

Ph

ase

(P

has

e#2

)

LEAN MANUFACTURING- 99

1.Analyze Current-State MAP

To complete this map you need the following:

• Team should physically walk through the process

• Obtain insight on how the process works

• Surface issues and solicit ideas for improvement

• Begin the analysis of the preliminary state map based on the data collected through the work

This is the map that present the current situation, and all symptoms/problems and wastes that need to be improved.



• Point out the value added, the pure non-value added, and the required non-value added

• Calculated and summarize the metrics

Metric Measurement

Value added %

Non-value added %

Quality ratio %

Lead times hrs

Workers productivity %

WIP inventory Batch size/ no of pieces/ tons

Cost $

Process Actual/Current Best Possible (Target)

Data Box (KPIs)

Each task/process is presented with the current measurement and the target.



Parking lot

Process Actual/Current Best Possible

Those are the tasks that you decided to work on later.

Process Map Analysis “Red Post-its Analysis”.

Process /issue description

Symptom/Problem Exists Total time


2.Develop a Future State Vision/Future State Map

This is the waste free map that has no waste in time or resources with the optimum/efficient cycle time and the no of resources needed. It also should present the right flow of the process steps.

Tips:

• Draw & write down all ideas of improvement from the team

• Allow people who manage the work day by day and have intensive experience about the process to share their ideas

• Consider the workers who do the work every day to put, and share their own ideas on how to improve these issues.



This map would include:

• The optimum lead time (cycle time) of each task in the process

• The optimized flow of the process

• The right no of resources

• Seven wastes free

• Use brainstorming for potential solutions

• Create a parking lot for things that have been surfaced so you will work on later

3.Implementation & Visual Tracking System

The use of the visual tracking system on field during the kaizen work and before drawing the future state map is a good idea to present the following:

• Obstacles found in the project.

• The progress and the percentage of completion.

• The responsibility of each task.

• Postponed, in progress, and completed tasks.

• Documentation & procedures.

• Train people on the new process.



Metric Unit of measure

Target Improvement Owner

Process Cycle time Days/hours

Non-value added %

Value added %

No of workers

Quality ratio %

WIP inventory No of pieces/tons

Lead time between processes

Hours/days

Delivery % on time

Productivity %

4. Evaluate measuring performance

Value Stream Mapping is a tool to ensure that process improvement effort:

1. Fit together from a process to process so that a flowing value stream

is developed.

2. Match with the organization’s targets.

3. Serve the requirements of the external customers.

The tools you need onsite while observing the real situation:

• A stop watch

• A graph paper

• A pencil

• An eraser

• Calculator



Inappropriate actions commonly performed by lean leaders when using the value stream mapping for removal of wastes on shop floors:

• Treats the VSM as a tool for process improvement rather than a method to ensure that process level improvement efforts: 1. Fit together from a process to process so that a flowing value stream is developed 2. Match with the organization’s targets 3. Serve the requirements of the external customers.

• Focus on maximizing the efficiency of an individual process on behalf of others without understanding the real situation at the factory floor. For example, maximizing the material flow through the production processes using small batches will put more effort and load on the transportation department and the crew will have to make more batches.


• Jump to the do phase to implement the plan without spending enough time gathering facts, colleting people’s ideas, training peoples. Processes tend to slip back if people have not been trained on the culture of continuous improvement. Also people who the work day by day must be allow putting their own ideas to improve their works and produce the future state map. They should believe that this is something to facilitate their work and make it much easier and safer.

• Metrics are used by the senior managers to evaluate the results and control the employee performance at the factory floor without understanding the obstacles that need to be removed to get stable results. Managers should act as facilitators for the improvement process. Also metrics should be used by the employee themselves to measure their own progress and define the requirements of the next step.

Productivity & capacity improvement through finding the bottleneck

Machine.1 Machine.2

Capacity=100 units per hour Capacity=70 units per hour

A product is passing through two machines, one is capable of 100peices/hrs, the other is only capable of 70 pieces/hr.

Assume perfect quality and no time waste, so what is the OEE for each machine?


Sustain Standardize

Shine

Sort Set in Order


Any successful 5S process must achieve the following:

Eliminate the seven deadly wastes from the process

Reduce ergonomics in the workplace

Provide a secure and safe environment for the working labors and staff

Increase workers morale and satisfaction

Improve the factory appearance to attract the customers

Increase the productivity of the workers



A place for everything, and everything in its place

7 to 8 out of each 10 lean projects fail as companies try to treat lean as toolkit, copying and pasting the techniques without trying to adapt the employee culture, manage the improvement process, and develop peoples.

Some Management Habits. What do you think about the following approaches?

Management by Objectives

Incentives and Rewarding System

Sink or Swim Mentality

Blame Culture

Lean Failure!


Toyota’s main pillars “4P”



Eng. Mohammed Hamed Ahmed Soliman

The American University in CairoEmail: [email protected]

[email protected]: +201001309903

References:

Liker, J. K. (2003). Toyota way. New York: MacGraw-hill.

Liker, J. K., & Convis, G. L. (2012). Toyota way to lean leadership: Achieving and sustaining excellence through leadership development. New York: MacGraw-hill.

Rother, M. (2009). Toyota Kata. New York: MacGraw-hill.

Ahmed, Mohammed. Hamed. (2013). Lean Transformation Guidance: Why Organizations Fail to Achieve and Sustain Improvement with Lean Methodology. International Journal of Lean Thinking IJLT, 4(1).

mailto:[email protected]

mailto:[email protected]

lean manufacturing

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