Developing a Standardized Approach to Work, Part 3

5S, the starting point for all things lean

Published: Thursday, July 1, 2010 - 06:00

In this four-part series, we take an in-depth look at how to design an effective work environment. Part one discusses the elements of continuous-flow work cells. Part two considers how to enhance the efficiency of such work cells. Part three explores the 5S methodology. In part four of the series, we look at single-minute exchange of die (SMED).

The standardized approach to work is completely dependent upon maintaining discipline in the workplace. Procedures are useless if they are not maintained and followed. Change is not only inevitable, it is also desirable and pursued continuously. When favorable change has been discovered, it is made part of the standard.

The workplace is the physical manifestation of the standard. It includes the materials, equipment, and tools needed to do the work according to the standard. It does not include anything that is not needed. Just as the work cell is laid out to produce maximum efficiency, the details are also arranged to achieve this goal. The necessary tools are placed where they can be easily and immediately accessed when needed. Strict housekeeping is enforced to ensure that clutter is nonexistent; clutter is not needed to do the work, so it should be eliminated.

In lean Six Sigma, the system used to create and maintain an efficient, clutter-free, and clean workplace is known as “5S,” which stands for sort, set in order, shine, standardize, and sustain. 5S is the starting point for lean deployment:

Sort. Clearly distinguish what is necessary to do the job from what is not. Eliminate the unnecessary.

Set in order. Put needed items in their correct place to allow for easy accessibility and retrieval.

Shine. Keep the workplace clean and clear of clutter. This promotes safety as well as efficiency.

Standardize . Develop an effective approach to maintaining a clean and orderly work environment. Integrate steps for prevention/elimination of clutter into work routine.

Sustain. Make a habit of maintaining your workplace. Create conditions to support 5S.

Sort

With 5S, the search for nonvalue-added waste occurs during the sort phase. Sort means that you vigorously search for items in the workplace that are not needed to perform the value-added work. This is much more difficult than it sounds. People tend to want to hold on to things “just in case” they are needed at a future time. This mentality is an artifact from the pre-lean era when unforeseen problems—such as equipment failures, quality defects, and bottlenecks—created such needs. This hoarding behavior results in accumulating objects that are not needed in the well-designed lean work cell. They take up space that is needed for production and they get in the way of smooth movement within the work cell.

Red-tagging

To deal with the “we may need this later” mentality and the general uncertainty regarding what is and is not needed, it is best to proceed by placing an item in a holding area before discarding it completely. In lean Six Sigma, this is done by using red tags. When a red tag is placed on an item, the team is asking three questions:

1. Is this item needed in this work cell?

2. If the answer to No. 1 is yes, is it needed in this quantity?

3. Does this item need to be located here?

Consider individually each item that is red-tagged and take one of the following actions:

• Leave it where it is.

• Move it to another location for storage.

• Hold it in a local red-tag holding area for a specified period of time to see if it is needed or not.

• Dispose of it appropriately, i.e., sell or give it away, use it elsewhere in the company, recycle or discard it, or move it to a central red-tag holding area.

If large equipment is red-tagged, it should be handled as described above whenever possible. If the equipment can’t be moved, it can remain where it is for a while, but it should be removed when it is determined that it is not needed where it is.

The results of the red-tag effort should be documented to show the value of the effort. It is not uncommon for companies to postpone or scrap plans to add facility space after seeing the amount of floor space freed as a result of the red-tag program. This is the infamous “hidden factory” made visible.

Set in order

Once the sort phase has been completed, it is time to set the remaining needed items in order. Arrange and label items so they are easy to find, access, and put away. When there is no need to search for an item or when the opportunity to select the wrong tool for the task is eliminated, value is added to every move you make. You’ll make fewer errors due to using the wrong tool or material or form.

Setting in order revolves around standardization, and, conversely, standardization revolves around setting things in order. The key principle is visual control, i.e., use painting, outlining, or signboard strategies. Figure 1 makes it clear to the surgical team which instrument goes where by providing drawings and verbal descriptions. In factories, lean Six Sigma teams often keep things simple by drawing outlines of the tools on simple pegboards, as shown in figure 2. It is then easier to see which items are currently in use, as well as where a given item needs to go when it is returned. If possible, attach the tool to a retractable cord so it automatically returns to the correct location when released (see figure 3). Color-coding the tools helps reduce errors.

Figure 1: 5S surgical instruments organizer

Figure 2: Pots and pans outlined on pegboard.

To further simplify, teams should organize tools so they are presented in the order of use and are easily accessible to operators. Ideally, operators will be able to get the needed tool without even looking at the tray or pegboard. This may require providing storage areas with additional space between tools to make it easy to reach them. ¹

As a general set-in-order rule, frequently used items are located nearer to the work cell than items used less frequently. Items that are seldom used are usually stored in a remote location to reduce clutter.

Figure 3: Color-coded tools and retractable cords above engine assembly line

Locations

The locations where work in process (WIP), jigs, tools, and other equipment are stored can be determined by evaluating the “5S map,” such as the work cell layout shown in figure 4. This is done as follows:

1. Draw the 5S map on a floor plan, preferably drawn to scale. Indicate the location of WIP, fixtures, tools, etc. on the scale drawing.

2. Draw a spaghetti diagram of the workflow on the 5S map. Identify wasted motion.

3. Create alternative 5S maps that reduce or eliminate wasted motion.

4. Simulate the workflow represented by the various 5S maps and choose the best alternative.

5. Create the new work cell layout, including locating the WIP, tools, fixtures, and jigs.

Figure 4: 5S map of work cell layout

Once the improved layout has been determined, create signboards to identify the locations for the various items needed in the work cell. This includes location indicators that show where the various items go, e.g., marking off floor areas with tape or paint. It also includes item indicators that show the specific items that belong in each location. Finally, you will need amount indicators to specify how many of each item are needed. Signboards are used to identify machine locations, locations for standard-procedure displays, storage of equipment when it is not being used, location of WIP and finished goods inventory, racks and spaces within racks for various items, and named work areas.

Floor locations are often shown in places other than the work cell itself. For example, paint (or colored tape) is used to show aisles and aisle direction, door swing space, storage locations, zones that are off-limits for storage, and hazardous areas. Additional information can be conveyed by using color-coded paint. For example, red might show off-limit areas, green might show operations areas, and yellow might indicate divider lines. ² If you use color-coding, be sure that the color uses are standardized.

Shine

Shine can be thought of as the lean Six Sigma version of housekeeping. It involves making sure that dirt, grease, and grime are eliminated from the work place. The goal is to make the work place a safe and pleasant place in which to work. Shine also ensures that items and equipment will be ready to use when needed. Shine is an ongoing activity, not a once-in-a-while “spring cleaning” event.

Cleaning and inspection go hand in hand. When you clean an area, you automatically inspect the working surfaces, floor, equipment, and parts that you are cleaning. This is a side benefit of cleaning because it highlights issues and opportunities that would otherwise be overlooked. To get the full benefit from this, you will need to incorporate a method for easily reporting any problems discovered.

Identify the shine targets. What warehouse items (e.g., parts, raw materials, and subassemblies) equipment (machines, tools, worktables, desks, and chairs) and spaces (floors, work areas, beams, windows, shelves, and lights) will be cleaned?

Assign responsibilities. Use the 5S map to create specific areas that will be assigned to individuals. Set up and post a schedule showing when each area is to be cleaned. Be sure that shine activities take place throughout each day.

Determine the shine methods. Start and end each shift with a shine inspection. Determine what will be cleaned and how it will be cleaned, including the cleaning supplies and equipment needed. Implement the “five-minute shine” drill. You will be surprised at how much can be done in an intense five-minute effort. Develop standard cleaning procedures that ensure that time is spent on actual cleaning rather than on preparation for the task.

Tools. Apply the set-in-order approach to your cleaning tools, thereby making them easy to find and easy to use.

Shine! Now it’s time to get to work on the targets. Have the responsible people follow the shine procedures and while using the proper tools, clean the work area to the required standards.

Deal with issues identified during cleaning. Finally, respond to any problems found during the shine process. When possible, fix things immediately. The standard cleaning procedure should include what steps to take to deal with problems that can’t be fixed at once. To whom should they be reported? What forms are needed? It is a good idea to attach a tag to any equipment where maintenance has been requested to remind workers and supervisors that maintenance is pending.

Standardize

Standardized cleanup is used to maintain the 5S activities described so far. The definition is somewhat circular: When the 5S activities of sort, set in order, and shine are properly maintained, then you have standardized 5S. When 5S has been standardized, you avoid backsliding.

Determine responsibilities

The tools needed for standardized cleanup include those already introduced: 5S maps and 5S schedules. In addition you’ll need a new tool: the 5S job cycle chart (see figure 5). To create such a chart, you sort the duties into sort, set in order, and shine categories and use a letter code to identify the cycle period. The resulting 5S job cycle chart can be used as a checklist by the personnel responsible for the various 5S activities.

Figure 5: 5S job cycle chart

Integrate sort, set in order, and shine with the work routine

Make these three 5S activities a part of the normal work done in the work cell. This integration will reinforce the idea that 5S isn’t something added on to the work being done; it is an integral part of it. One mechanism for implementing this is “visual 5S.” As with the visual workplace in general, the purpose of visual 5S is being able to tell at a glance that 5S activities are being done on an ongoing basis. For example, if set in order requires that tools are kept on a pegboard, then the tool outlines on the pegboard will indicate which tools are currently in use. This means that any blank space observed on the pegboard at the start or end of the shift is an indication of a problem.

Another mechanism is five-minute 5S. This is similar to the five-minute shine described earlier, only the scope is the entire 5S program. Don’t get hung up on the “five-minute” part of this activity; it’s just an easy-to-remember tag. However, think of it as something you do quickly. You may want to use a visual display, such as the one shown in figure 6, to make it easier to track your five-minute 5S activities.

Figure 6: Five-minute 5S signboard

Sustain

Sustain is the name of the whole 5S game. You gain nothing by deploying the first four S disciplines only to let things go back to business as usual in the long run. In fact, you probably create an attitude among workers and supervisors that management isn’t really serious about lean Six Sigma.

Just why things tend to get worse unless we pay close attention to them is a debatable proposition. There is an analogous concept used in thermodynamics: entropy. One definition of entropy is applied to human systems—“the inevitable and steady deterioration of a system or society.” In physics, entropy is inevitable in closed systems. These are systems where there is no additional input of energy. The same applies to lean Six Sigma 5S systems: If no additional effort is put into sustaining the improved state, then deterioration is inevitable and steady. You simply have no choice. If you want to sustain the benefits of 5S, you must put forth the required effort to do so. Here are some guidelines to help.

• Provide periodic refresher training on 5S.

• Schedule the required time to perform 5S on a daily basis.

• Create a standardized approach to 5S that clearly spells out how 5S will be implemented.

• Have your lean Six Sigma process owner acknowledge and accept ownership of 5S.

• Create programs to recognize 5S efforts and reward compliance with standards.

• Keep 5S fun! Think of creative ways to keep 5S from becoming drudgery. (Five-minute 5S contests, anyone?)

Safety—the real first S

A workplace where 5S is practiced is not only clean and well-organized, it is also safe. Clutter and unnecessary materials and equipment contribute to accidents. People can locate the tools and materials they need without searching among unneeded objects and moving them out of the way. There are no oil spills where people can slip and fall. Adequate and clearly marked aisles make transportation safer. Marked storage areas that contain only what is needed are less likely to have excess inventory that can fall and injure people.

Coming up

Part four looks at single-minute exchange of die (SMED).

Notes:

[1] In the case of the surgical instruments tray, a person normally hands the needed instrument to the surgeon.

[2] Color coding has other uses as well. For example, it can be used to show  which tools are used together, which equipment make up a “set” for producing a particular item, etc.. Be creative and use your imagination to identify how to use simple, visual means of conveying information at a glance.

About The Author

Tom Pyzdek

Thomas Pyzdek’s career in business process improvement spans more than 50 years. He is the author more than 50 copyrighted works including The Six Sigma Handbook (McGraw-Hill, 2003). Through the Pyzdek Institute, he provides online certification and training in Six Sigma and Lean.