Posts Tagged ‘flow work’

Lean Six Sigma Improvement and Work Design, Part 4

Monday, July 5th, 2010

This is the fourth post in a series taken from a lesson in Pyzdek Institute Lean Six Sigma Black Belt training. Future posts will continue the topic. You can find all of the articles in the series by searching this site for the title.

What methods should be used to accomplish the goal using the resources (materials, machines, and manpower) that we have?

What standard work procedures should everyone follow? (Standard Operations Routine Sheet)

Designing continuous flow work cells involves developing standard operations. These are descriptions of work that combine people, equipment and materials to create value as effectively as possible. The components of standard operations are takt time, the work procedure, and the parts and materials essential to start work within the process, including parts or materials at the machines. If all three of these components are not present, standard operations cannot exist.

At companies like Toyota standard operations are determined by the foreman. Toyota foremen are masters of the work being done by their employees. Foremen are able to demonstrate the standards to their people. If an impartial observer agrees that the pace of work being done by the foreman following the standard is appropriate, then Toyota expects workers to adhere to the standards.

In many companies, however, things are done differently. It is my experience that there are few foremen who are able to do all of the work being done by their employees. The history of management in America and most European countries has led to a system where work is designed by experts in work design (industrial engineers,) supervised by experts in management (foremen and supervisors,) and performed by blue-collar specialists at a given trade (machinists, assemblers, welders, assembly line workers, etc.). This model worked adequately[1] in the past for batch-and-queue systems where specialization was the norm, but it is no longer possible to remain competitive using this approach.

However it raises a question: if we don’t have a well-rounded supervisor to design work, how can it be done? The answer arrived at by many companies is to use teams. Teams designing and analyzing work are provided with basic training in the principles of work design, inventory control, and lean; that’s what this lesson and previous lessons are all about. The team must include at least one member who is highly skilled at the work done at each process in the subproject loop. Preferably this will be the same person, but if there is no such person available the team may have more than one skilled worker. Once the work of several people/machines is combined into a work cell, the company will need to cross train all of the workers in the cell so that they may help one another.

It may be that no one person on the team knows as much about work design as the industrial engineer, or as much about management as the business school graduate, or as much about any operation as the blue-collar journeyman, but experience has shown that tremendous improvements are possible using the team approach–if the company leadership truly embraces the Lean philosophy.

Standard operations are the sum total of all of the ways that people, materials, equipment, and information combine to create value. There are three components to standard operations:[2]

  • Cycle time
  • Work procedure (work sequence)
  • Standard stock on hand (WIP)

Each of these items is required to standardize the operations.

Are there any “tips” that people should know about doing the work?

Knowledge of work is often a collection of insights. Experienced people have developed tricks that make it easy to do the task at hand, or help them avoid problems that might causes injuries or quality issues. When designing the work you should create a document that can be given to workers showing them what to look for. This will include such things as the work sequence, how to handle the items, how to set up the tools needed for the job, and other relevant work details. The emphasis is on specific, concrete directions. Avoid abstractions. Include drawings, videos, pictures, animations, and other media to help show the proper way to do the work. Flowcharts are often helpful.

A good model for work instructions are the instructions provided to customers for assembling products. Figure 4 shows the instructions for assembling a baby’s crib. It includes step-by-step directions, drawings, safety warnings, tips on how to put the crib together more easily. It also includes tips on maintenance, cleaning, and storage; guidance on how to test your work to assure that it’s done correctly; instructions on changing the crib into a toddler bed; etc.. Think of work instructions as the workplace counterpart to assembly instructions for consumers and you’ll have a good idea of what’s needed. The idea is to provide simple, easy-to-understand, and complete instructions.

Figure 4-Crib Assembly Instructions




Figure 4-Crib Assembly Instructions

Figure 4-Crib Assembly Instructions




Manual of Work Directions

The manual of work directions tells how to perform the standard operations properly. It is based on the production capacity table (e.g.,
Figure 3 in an earlier article) and the standard operations routine sheet. It describes the work to be done by each person in the work cell. In addition, the manual includes:

  • Safety and quality items for each step in the work sequence;
  • Illustrations of machine placement for work performed by each individual worker;
  • Cycle time for each operation;
  • Work sequence;
  • Standard stock on hand;
  • Instructions for checking quality.

Machine placement is shown on a separate sheet of 11×17 paper (A3 paper.) The sheet will have columns showing work sequence, standard stock on hand, cycle time, net operating time, and safety and quality checks. The completed sheet is called a Standard Operations Bulletin (see Figure 5.) Standard Operations Bulletins are displayed at the line and show the workers what is expected of them. In addition, supervisors can use the bulletins as visual control tools to audit compliance with work instructions. Managers and Process Improvement Teams can study the bulletins for ideas on improving the work.

Figure 5-Standard Operations Bulletin Example[3]




Figure 5-Standard Operations Bulletin Example

Figure 5-Standard Operations Bulletin Example





[1] This is a debatable premise today, but it isn’t fair to judge past behaviors by current day standards.

[2] Kanban Just-in-Time at Toyota, 1989, Lu, David J. translator, Productivity Inc., Portland, OR., p. 101.

[3] Kanban Just-in-Time at Toyota (1989), Productivity Press, Portland, OR. P. 114.

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Lean Six Sigma Improvement and Work Design

Monday, June 14th, 2010

This article is an excerpt from a lesson in Pyzdek Institute Lean Six Sigma Black Belt training. Future posts will continue the topic.

In previous lessons you learned how to change a traditional batch-and-queue value stream into a lean value stream. Now we will discuss the design of the actual work that will take place within the processes of the value stream. By going a level deeper we will be able to improve the flow of work within the different processes in the value stream. Specifically, you will learn how to design continuous flow work cells. While the discussion here focuses mainly on manufacturing work cells, the lean principles described apply to any work, including that done in administrative, transaction, or services such as healthcare, retail, and so on.

Selecting Subprojects

The first step is to identify subprojects within the value stream. Subprojects, sometimes called project “loops,” are determined by looking at the future state value stream map and choosing groups of related processes in the value stream for improvement analysis. Each subproject will require a different team with its own set of knowledge, skills, and abilities. However, it is desirable to have at least one member of the Lean Six Sigma team who participates on all of the subproject teams. Figure 1 shows a future state value stream maps with subprojects identified.

Figure 1-Subproject “Loops”

Subproject Loops

Once subprojects are identified, the Lean Six Sigma team must decide which to pursue first, second, and so on. As a general rule it is a good idea to begin at the customer end of the value stream and work backwards. This provides the customer with improved service that they can see and feel quickly. Another criterion is that the pacemaker process should be improved early, since it sets the pace for the rest of the value stream. The “Inside-Out Rule” should be observed: get your own house in order before extending your improvement efforts to include the value streams of outside customers and suppliers. Of course, your decision regarding the starting point should also take into account the likelihood that the subproject will have a big impact on the business and its customers.

Don’t think of the future state value stream map as untouchable. If, as you go through the exercise of selecting and prioritizing subprojects, you see an obvious improvement that’s not on the map, revise the map. Remember, the goal is to improve as much and as quickly as possible.

Once the subprojects have been identified and prioritized, treat each of them as you would any project. You may want to review the modules covering project management in the Define phase at this time. For each project find a sponsor (the value stream owner is a good candidate,)  write a charter, select a team, develop a schedule, identify stakeholders, etc..  By now these things will be second nature to you.

Elements of Work

Figure 2 shows the relationship between value streams, processes, operations, workplaces and procedures in the creation of value. The relationship is hierarchical. To implement Lean all levels of the hierarchy are considered. In previous lessons we discussed ways to change value streams by replacing batch-and-queue push scheduling systems with lean value streams where work is scheduled to maximize flow. Several other lessons focus on ways to improve processes, the next level of the hierarchy. For example, by using process maps to see how work flows through processes or by identifying non-value-added work. In designing work cells we will go deeper than the process level and look at the design of operations, including the layout of workplaces and the standard procedures followed to perform the work in each operation. Such operations are known as standard operations, because the way work is performed follows strict standard procedures.

Figure 2-Value Creation  Hierarchy



Value Creation Hierarchy

Value Creation Hierarchy



Processes are distinct sets of operations nested within a value stream. Process improvement has been the topic of numerous lessons in this course and it requires knowledge of the root causes creating process problems. In the context of designing continuous flow work cells in Lean Six Sigma, we focus primarily on the things in a process that inhibit flow, such as

  • Non-value added process steps on the opportunity map
  • The distance people, materials, or WIP travel between process steps (from the spaghetti chart)
  • Changeover, setup and adjustment time (discussed below)
  • Identify the root causes that are creating quality issues that are responsible for scrap, rework, or problems downstream (discussed in later modules)

In Lean Six Sigma we design work cells that improve the process as well as the specific operations within a cell. We get into “nitty-gritty” details of the work itself, considering how materials are handled and moved, fixtures, workplace layout, movement of various workers, etc. The transfer of work elements  (small units of work) between workers is carefully considered. “Work” is the sum of all of the work elements required to create one complete unit through the entire value stream.

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What is Six Sigma?

By Thomas Pyzdek, Author of The Six Sigma Handbook

For Motorola, the originator of Six Sigma, the answer to the question "Why Six Sigma?" was simple: survival. Motorola came to Six Sigma because it was being consistently beaten in the competitive marketplace by foreign firms that were able to produce higher quality products at a lower cost. When a Japanese firm took over a Motorola factory that manufactured Quasar television sets in the United States in the 1970s, they promptly set about making drastic changes in the way the factory operated. Under Japanese management, the factory was soon producing TV sets with 1/20th the number of defects they had produced under Motorola management. They did this using the same workforce, technology, and designs, making it clear that the problem was Motorola's management. Eventually, even Motorola's own executives had to admit "our quality stinks." Read More...