If most managers treat 5S as a cleaning program, how can we believe that 5S is the cornerstone of continuous improvement? By overlaying the 5S on top of each of the eight wastes, we can further our understanding of how the 5S is NOT a cleaning schedule, but rather a way of thinking about work.
The eight wastes defined by Taiichi Ohno, creator of the Toyota Production System, are:
1.Inventory
2. Overproduction
3. Defects
4.Movement
5. Transportation
6. Waiting
7. Overprocessing
8. Underutilized people or specifically the minds of people.
5S is NOT a cleanup campaign. If a cleanup campaign were essential, many companies would hire and permanently hire auctioneers to sell unnecessary materials, interior designers to paint and scratch the factory plaid, and cleaning crews to keep the factory spotless. This is the logical conclusion of the founding cleanup campaign, yet we rarely see this level of commitment to such a program. So let’s apply the 5S system to the eight wastes and see if we can achieve some clarity of thought on this subject. I suggest to you, the curious reader, eternally searching for meaning behind innocent systems that prove impossible to succeed due to our inability to execute with simplicity, that the 5S system is a thought process. That it is used primarily in the business of keeping factories clean and tidy and marginally safer is a convenient way to prevent managers from stepping over the improvement barrier, losing important control power to the millions of potentially brilliant workers in the industry. American industry. 5S is NOT a cleanup campaign, it’s a thought process. In theory, a thought process is a philosophy. Soon, we can begin to understand why 5S is considered a cornerstone, a foundation on which to build all other knowledge and improvement experiences. I ask for your patience while I apply the 5S’ through the Eight Wastes. The following are the many points that detail how 5S is a thought process.
Filtering our INVENTORY view with 5S thinking.
We start with inventory, as many feel it is the blanket for all other waste. With inventory we realize the seven subordinate wastes: Obsolescence, Excess capital and poor cash flow due to overproduction, Waiting due to the slow moving nature of inventory, Defects we produced that slipped through our system quality sampling, movement as we rush to make products we don’t need, excessive transaction processing for unnecessary inventory, hauling in unneeded products and wasted ideas, underutilized minds as we were busy making products that weren’t needed . What improvement ideas can we generate if we can’t see the problems hidden by mountains of inventory? Inside the mountain, there are caverns filled with treasure chests full of trouble! Do you dare to enter?
Using the English word and combining it with the Japanese meaning, let’s ‘sort’ our inventory. What is really needed? Do we have the correct amount? Let’s determine the actual demand at the point of sale and size our inventories for those demands. This is done where flow cannot be achieved. Is it the type desired by the client? If not, let’s determine the correct types and quantities and ‘set’ this inventory in an orderly fashion. What does this mean: ordered? Is it now ready to be removed by the next post process? Are you in the right area? Is it arranged in such a way that the client making the withdrawal can take the correct amount and the correct type, avoiding mistakes? Is it presented in an easy way? Are you, as a manager, looking at all of these type and configuration characteristics within the inventory management process? Is it clear what is really needed? Do you go to the genba and do the white glove test for inventory? How much, right type, right place, right time? We inspect the cleanliness of work areas, but we must also inspect the standards we create by sorting and tidying them up. Are we maintaining the inventory reduction effort by determining new and better ways to operate the process? The improvements will allow us to reduce inventory, furthering our problem-solving effort.
Inventory also exists in the office. In your organization right now, how many unread emails, response delays, piles of purchase orders, waiting approvals, lots of time cards, and many other administrative bottlenecks are there really? When you think about it, the same rules for physical product inventory apply to these office inventories. Why can’t we agree on system behaviors around emails, or limits on purchase orders, or processing timecards daily instead of weekly? Deviations from these standards would indicate potential problems or anomalies, things we didn’t expect to happen. By doing so, we create the flow of these processes. Since we are modifying a person’s work area in the office, we are infringing on personal space much more intensely than in the shared space of a warehouse or production plant. It’s even more important to adopt the 5S thought process from the point of view of the person when it comes to office workflow.
Lesson learned
When we put the 5S system in the context of wasted inventory, we first look at what is needed from the customer’s point of view. Once determined, we set things up in an orderly fashion so inventory is ready for pick up. This is perfectly aligned with the concept of Just-In-Time thinking. We can use some tools like kanban and continuous flow to achieve this order, but regardless of the tools used, the inventory is ready in the right amounts, the right types, in the right place, and at the right time. When we sweep the area or perform a gloss inspection, we are inspecting the system for contamination. In this example, contamination is inventory outside acceptable kanban limits, or inventory in the wrong location, or finished goods defects. Just like hand washing your car in the driveway, inspecting the job site is a personal experience. You wash the windshield and see the wiper blade separate from the frame. You take corrective action now, in the safety and comfort of your own home, not on the busy snowy highway on your way to a family reunion or important meeting. Sanitizing helps us avoid accidents in this way. Everything is supposed to be normal, if not, then in the case of the wiper blade, the situation goes from safe to unsafe. So, do the same type of inspection on the job site. Go to inventory locations. Visualize normal job site limits and levels so your inspection can be done in a series of quick glances. Are they within limits? If not, your system is contaminated with variability: you must sanitize the system. It has gone from a state, “in control of cost, quality and productivity” to “out of control”. That’s why Ohno once said that the word ‘disinfect’ is a better term for sixo than ‘shine’ or ‘sweep’.1. When American managers say ‘sweep’ or ‘shine’ we lock ourselves into thinking that 5S is about cleaning. It is NOT about cleaning. The third S is about sanitization, the extermination of contamination in all its various forms, from the process. From now on, I will always use the word ‘sanitize’ for the third S. If we use the word sweep, we think of cleaning. As simple as it may sound, it’s the main reason why 5S is a cleanup campaign in the US.
Standards are the rules you have established for your inventory regarding classification, configuration, and sanitization. Using the standards should be an easy job; otherwise, people won’t use them. Good standards are exemplified through a visual workplace. Through the use of images we can determine if normal or abnormal conditions exist. Visual or standard indicators should be something useful and meaningful to people working in the genba. For example, a fixed number of kanban cards placed in a kanban station tells the manager how much inventory is in the system. If the kanbans are not located in one place, it can be difficult to determine what is normal. If bin quantities are not standardized, it can be difficult to understand how much inventory should be in the system, or how much to run, or possibly fill a non-standard bin with the wrong type. Ambiguity in standards forces people to make decisions. Clear standards allow people to simplify decisions and make the right decisions. Red means stop, green means go. Yellow means two things to people: 1) caution, this light is about to turn red, or 2) speed up and try to get there before it turns red! Ambiguity is the killer of good standards. It is your job as a manager to remove this uncertainty from the process, simplifying the millions of decisions that need to be made. Think of it this way. If there are ten thousand small tasks in your personal work area, that means there are at least twenty thousand different results. We all know that five mechanics will do a job in five different ways. So if the mechanic’s job involves 500 tasks, then we can expect 2,500 different ways of doing the job. The same is true of inventory and the decisions that are made to manage that inventory. This is the sustain part. Encouraging people to simplify decisions in kanban and inventory management is a small form of real empowerment and participation. It is an opportunity to teach others who work in the genba why inventory reduction is important. There are teaching opportunities around every corner, every day, in the genba.
In Part III, we apply the 5S to other waste.