Failure Mode and Effects Analysis (FMEA)

Failure Mode and Effects Analysis (FMEA) was one of the first systematic techniques for failure analysis. It was developed by reliability engineers in the 1950s to study problems that might arise from malfunctions of military systems. A FMEA is often the first step of a system reliability study. It involves reviewing as many components, assemblies, and subsystems as possible to identify failure modes, and their causes and effects. For each component, the failure modes and their resulting effects on the rest of the system are recorded in a specific FMEA worksheet. There are numerous variations of such worksheets. A FMEA is mainly a qualitative analysis.

A few different types of FMEA analysis exist, like

• Functional,
• Design, and
• Process FMEA.

Sometimes the FMEA is called FMECA to indicate that Criticality analysis is performed also.

An FMEA is an Inductive reasoning (forward logic) single point of failure analysis and is a core task in reliability engineering, safety engineering and quality engineering. Quality engineering is specially concerned with the "Process" (Manufacturing and Assembly) type of FMEA.

A successful FMEA activity helps to identify potential failure modes based on experience with similar products and processes - or based on common physics of failure logic. It is widely used in development and manufacturing industries in various phases of the product life cycle. Effects analysis refers to studying the consequences of those failures on different system levels.

Functional analyses are needed as an input to determine correct failure modes, at all system levels, both for functional FMEA or Piece-Part (hardware) FMEA. A FMEA is used to structure Mitigation for Risk reduction based on either failure (mode) effect severity reduction or based on lowering the probability of failure or both. The FMEA is in principle a full inductive (forward logic) analysis; however, the failure probability can only be estimated or reduced by understanding the failure mechanism. Ideally this probability shall be lowered to "impossible to occur" by eliminating the (root) causes. It is therefore important to include in the FMEA an appropriate depth of information on the causes of failure (deductive analysis).

Important of Listening

Production Leveling (Heijunka)

Production leveling, also known as production smoothing or – by its Japanese original term – heijunka is a technique for reducing the muda (waste). It was vital to the development of production efficiency in the Toyota Production System and lean manufacturing. The goal is to produce intermediate goods at a constant rate so that further processing may also be carried out at a constant and predictable rate.

On a production line, as in any process, fluctuations in performance increase waste. This is because equipment, workers, inventory, and all other elements required for production must always be prepared for peak production. This is a cost of flexibility. If a later process varies its withdrawal of parts in terms of timing and quality, the range of these fluctuations will increase as they move up the line towards the earlier processes. This is known as demand amplification.

Where demand is constant, production leveling is easy, but where customer demand fluctuates, two approaches have been adopted.

1) Demand leveling and

2) Production leveling through flexible production

To prevent fluctuations in production, even in outside affiliates, it is important to minimize fluctuation in the final assembly line. Toyota's final assembly line never assembles the same automobile model in a batch. Instead, they level production by assembling a mix of models in each batch and the batches are made as small as possible. This is in contrast to traditional mass production, where long changeover times meant that it was more economical to punch out as many parts in each batch as possible. When the final assembly batches are small, then earlier process batches, such as the press operations, must also be small and changeover times must be short. In the Toyota Production System die changes (changeovers) are made quickly (SMED). In the 1940s changeovers took two to three hours, in the 1950s they dropped from one hour to 15 minutes, now they take three minutes

Benefits of Heijunka

1.      Flexibility As we are getting more MSR (Musical Size Run), we need to produce all sizes each day in order to reduce inventory at the end of the line.

2.      Optimization of material inventory levels at all levels an departments

3.      Balanced use of labor and machines(level workload across processes)

4.      Smoothed demand on upstream processes and the plant’s suppliers.

5.      Reduce security risk (seal boxes as soon as possible)

QCO (Quick Changeover)

QCO can be termed as rapid & efficient way of converting a process from running the current product to running the next product. An organized process continuously reduces the setup time. QCO stands for Quick change over.

The time from the last good part till the first good part is produced after the changeover called as QCO time.

QCO can divide in to two sections.

1.      Internal Setup: Activities that must be performed while the machine is shut down or idle

2.      External Setup: Activities that can be performed while the machine is running or producing

Most important activity is converting internal activities in to external activities.

Where does the term QCO came from?

Land cost in Japan were very high, therefore it was not feasible to store large inventories of vehicles.

Therefore, they were searching for a solution and because of that QCO process started by Toyota vehicle manufacturer.   

Who invented QCO Process?

Developed by Shigeo Shingo

(In the late 1950’s & early 1960’s chief engineer of Toyota)

Born in 1909 & passed away on 1990

External consultant for TOYOTA since 1950’s

Famous with the POKA YOKE & SMED

How does QCO relate to other lean tools and concepts?

It really compliments anything in TPS (Lean Manufacturing). In fact we sort of cringe at the notion of calling it a tool. Waiting is one of the wastes out of seven wastes and mainly we can reduce that by using QCO. 

Figure 01: Practical Example for QCO

Lean Manufacturing: Pareto chart and 80%-20% Rule

Lean Manufacturing: Pareto chart and 80%-20% Rule: The Pareto Chart and the 80:20 rule are useful tools to drive Continual or continuous process improvement. If you want your business to flo...

Pareto chart and 80%-20% Rule

The Pareto Chart and the 80:20 rule are useful tools to drive Continual or continuous process improvement. If you want your business to flourish and stay ahead of your competition then you need to stay ahead of them in all aspects of your business. A pareto chart is one tool that you could use to help you stay ahead of the competition. The pareto Chart will highlight the vital few areas for you to target to tackle the bulk of your problems.

The 80:20 rule can help you identify the 20% of the causes that create 80% of the effect allowing you to focus on those vital 20% for maximum benefit rather than wasting your resources tackling the other 80% of the causes for minimal benefit.

The Pareto chart and the 80:20 rule are powerful tools to help you focus your resources effectively for maximum benefit and are very simple tools to use.

History of the Pareto Chart

Vilfredo Pareto discovered his “pareto principle” whilst studying the distribution of wealth for his works, he found that 80% of a countries land was owned by just 20% of it’s people. There is some argument as to the origin of his data however, it is often attributed as being based on Italian data as he was an Italian, however it is more likely that the data used was in fact from the UK. This principle was further expanded upon by the quality Guru Joseph Juran who applied the Pareto Principle across many industrial statistics.

By using a quality tool such as the pareto chart and the 80:20 Rule you can drive continuous process improvement.

The 80 20 rule is not always the right ratio, quite often we see 95 5 for instance or 60 40, however the 80 20 rule was the first ratio seen and identified and the one that seems to fit the majority of scenarios, therefore it is commonly used as a method to identify the vital few causes to the majority of our issues.

Directions for the map Pareto Chart

1.    Collect data about the contributing factors to a particular effect

(for example, the types of damages discovered in particular style).

2.    Order the categories according to magnitude (Descending order) of effect

(for example, frequency of damages).  If there are many insignificant categories, they may be grouped together into one category labeled “other.”  

3.    Write the magnitude of contribution (for example, frequency of error) next to each category and determine the grand total. Calculate the percentage of the total that each category represents.

4.    Working from the largest category to the smallest, calculate the cumulative percentage for each category with all of the previous categories.

5.    Draw and label the left vertical axis with the unit of comparison

 (for example, “Number of Damage ” from 0 to the grand total).  

6.    Draw and label the horizontal axis with the categories (for example, “Type of damage”), largest to smallest from left to right.

7.    Draw and label the right vertical axis “Cumulative Percentage,” from 0 to 100 percent, with the 100 percent value at the same height as the grand total mark on the left vertical axis.  

8.    Draw a line graph of the cumulative percentage, beginning with the lower left corner of the largest category (the “0” point).

9.    Analyze the diagram to indicate the cumulative percentage associated with the “vital few”

(Using 80:20 Rule )

Identify the Vital Few

The whole purpose of our Pareto analysis is to identify what many call the "Vital Few". With the effect we are looking at (Rejects, stock value, poor customers, absent employees etc.) being caused by only a small percentage of the population we are examining we are looking to identifying those vital few on which we can concentrate our actions.

By concentrating our actions on the vital few we ensure that we get the greatest impact from our actions and the greatest return on our investment

Pareto Principle, 80 20 Rule Examples

·         80% of your rejects are caused by 20% of the causes, so tackling this 20% will eliminate the bulk of your problems.

·         80% of the value of your stock is made up by 20% of the quantity, so if you need to reduce your stock value to free up cash you identify the most efficient way to spend your time.

·         80% of your profit comes from 20% of your line items, so the remaining 80% are not as important if you have to prioritize your production or decide which to phase out.

·         20% of your suppliers supply 80% of your goods, so if you need to work on supplier development these are the ones to work with first.

·         80% of your sales come from 20% of your clients, so who do you focus on?

·         80% of time off work will come from 20% of your employees, so you know which to spend time with.

·         80% of your time on this document will be spent looking at only 20% of it’s content, maybe?

Yamazumi Charts

Yamazumi ?

A Yamazumi chart is a stacked bar chart that shows the balance of cycle time workloads between a number of operators typically in an assembly line or work cell. The Yamazumi chart can be either for a single product or multi product assembly line. 

 Yamazumi is a Japanese word that literally means to stack up. Toyota uses Yamazumi work balance charts to visually present the work content of a series of tasks and facilitate work balancing and the isolation and elimination of non-value added work content.

Standard Work Sheets (SWS)

Standardized work is one of the most powerful but least used lean tools. By documenting the current best practice, standardized work forms the baseline for kaizen or continuous improvement. As the standard is improved, the new standard becomes the baseline for further improvements, and so on. Improving standardized work is a never-ending process.

Standardized work consists of three elements:

• Takt time - which is the rate at which products must be made in a process to meet customer demand.
• The precise work sequence in which an operator performs tasks within takt time.
• The standard inventory, including units in machines, required to keep the process operating smoothly.

Supervisory Development Program -- Think Out of Box

Supervisory Development Program -- Important of Communication

Lean Manufacturing: Basic Introduction about “Andon Systems”

Lean Manufacturing: Basic Introduction about “Andon Systems”: Andon is a manufacturing term referring to a system to notify management, maintenance, and other workers of a quality or process problem...

Basic Introduction about “Andon Systems”

Andon is a manufacturing term referring to a system to notify management, maintenance, and other workers of a quality or process problem. The centerpiece is a signboard incorporating signal lights to indicate which workstation has the problem. The alert can be activated manually by a worker using a pullcord or button, or may be activated automatically by the production equipment itself. The system may include a means to stop production so the issue can be corrected. Some modern alert systems incorporate audio alarms, text, or other displays.

An Andon system is one of the principal elements of the Jidoka quality-control method pioneered by Toyota as part of the Toyota Production System and therefore now part of the Lean approach. It gives the worker the ability, and the empowerment, to stop production when a defect is found, and immediately call for assistance. Common reasons for manual activation of the Andon are part shortage, defect created or found, tool malfunction, or the existence of a safety problem. Work is stopped until a solution has been found. The alerts may be logged to a database so that they can be studied as part of a continuous-improvement program.

A3 thinking

What is an A3 report?  

An A3 report is simply an 11 x 17 inch piece of paper outlined into several structured sections. The exact structure depends upon the type of A3 and the needs of the situation. A general one consists of the following pattern 1) Background, 2) Current Situation & Problem, 3) Goal, 4) Root Cause Analysis, 5) Action Items / Implementation Plan, 6) Check of Results, and 7) Follow Up. The report is used to standardized and simplify report writing, proposals, status updates, and other common methods of communication. The content follows the logic of the Plan-Do-Check-Act cycle.

Where does the term A3 Thinking come from?

The term A3 Thinking was coined in English by our mutual friend Al Ward who passed away several years ago in an unfortunate accident.  In Japanese it is simply referred to as "A san" where "san" is the pronunciation for the Japanese number three.

Who invented A3 reports?

There is really no single inventor of A3 reports. Former manager of training at Toyota Isao Kato describes it more as a combination of forces including the PDCA cycle, the basic steps for a QC circle, the Toyota concept of making things visible at a single glance, and the humorous anecdotes of Taiichi Ohno refusing to read more than the first page of written reports. Instead he'd say "let's go and see" and make people "get the facts" while he tested their thinking.

How does A3 relate to other lean tools and concepts?

It really compliments anything in TPS (Lean Manufacturing). In fact we sort of cringe at the notion of calling it a tool. The last thing we want to see is another movement of starting QC Circles or drawing Value Stream Maps just for the sake of the activity. A3 Thinking is about a logical and critical thinking process that can be applied in any discipline. Think of it is a thinking pattern to be used in problem solving, improvement or any activity rather than a tool.