This concept is one of the more famous topics in the Toyota Production System yet I don’t see a lot of companies applying it correctly. Often times they struggle for a variety of reasons. All too often I see companies attempting to put the proverbial square peg in a round hole with regards to Standardized Work. One naive assumption is that Standardized Work is the only type of documentation on the shop floor of Toyota and will work for everything. In reality nothing could be further from the truth. A quick assessment of a machining plant inside of Toyota when I was an employee in Japan highlighted that true standardized work charts equaled less than 10% of the documents on the shop floor for example.
What else exists you might wonder? In general we thought of documentation in manufacturing (leave out product development, process engineering, purchasing, and other functions as that is another story entirely) as residing in one of four categories as shown on the following chart.
Work standards are the largest category of documents on the shop floor in Toyota. Often these are posted on the shop floor as well or are contained in binders depending upon the exact document. These work standards are fairly static documents where the contents don’t change very often. Quality check sheets, gauge usage instructions, tooling layout drawings, operation drawings and other technical documents are sample items in this category. Note that these documents come in a variety of shapes and sizes, etc. but the common denominator is that they do not have any link to takt time and thus do not need to change monthly unlike Standardized Work.
Another important category of documents in manufacturing is that of Job Instruction. Job breakdown sheets exist for many jobs in Toyota and are created and stored on an as needed basis. These forms are the items used in initial training for new operators. The contents are far more friendly than Standardized Work and consist of the main steps for a job, the key points in terms of safely, make or break points for quality, and ease for the job, as well as the reasons why we do it this way. These forms are what I typically have clients use who are just starting out with lean concepts or do not have the repetitive volume of Toyota for example. The training within industry (TWI) blogspot shows a generic sample of one such form.
A third category of documents that are used on the shop floor are which we can call tools for work study or improvement (e.g. Kaizen). There are a variety of these specific items such as time study sheets, work element analysis sheets, or forms for motion study. These items are never posted and just constitute a category of items that are used in Toyota.
The final category is of course the most famous section of all – Standardized Work. Pure Standardized Work only exists in Toyota when certain preconditions are met. For example there must be repetitive demand, the work pattern must be cyclical and repeating in nature, and the equipment should exhibit minimal trouble from quality or downtime problems. If these preconditions are not met then you are either better off using something different or fixing the problems that prevent usage of standardized work.
Pure Standardized Work in its final form also must include three different elements in order to qualify as Standardized Work. Those three elements are 1) Takt Time, 2) Work Sequence, and 3) Standard Work in Process (SWIP). One example of an old Standardized Work Chart in Toyota is as follows. Note that other types of Standardized Work forms have been used over the years in Toyota however this was the actual example used in training.
Notice the actual level of detail in the words describing the major steps. One common misconception that I find with Standardized Work is that it attempts to over specify the work in terms of motion and detail. There is no need to include that level of detail if proper training is conducted using Job Instruction and if items such as Work Standards are properly used as well. Since some companies skip using the JI forms and training method or are not clear on the need for Work Standards they attempt to shoe horn everything into a Standardized Work Chart and turn it into a mess that no one really follows or uses. The result is confusion and a document that does not function in its intended fashion.
In a Toyota plant with proper supporting documentation the above type of example was what supervisors relied upon to determine if the process was being followed or not. Generally several stations were observed per day for coaching reasons or to see why certain operators might be struggling to keep up with the prescribed pace of the job. The form also had to be changed monthly as takt time changed. When demand fluctuations triggered a change in takt time then the amount of work that any one operator would handle would change as well. As a result additional major steps might be added to the job if takt time slowed down, or be subtracted if take time increased to a faster speed. In this way Toyota balanced labor to the demand rate of the customer each month and added or subtracted the number of workers on a given line. This form is also a good place to use for thought starters to generate improvement ideas as well.
In order to create the above example two additional forms had to be created as well. The first is the Process Capacity Chart and the second is the Standardized Work Combination Table. Examples are highlighted below but I will not explain the details behind them in this post.
I have placed the old basic training materials we used for teaching Standardized Work on line at this location (click for the web page) for those interested. My only caution is that the magic is not in the forms or the trainers guide. Just like possessing the same golf clubs as Tiger Woods does not necessarily make you a better golfer obtaining these forms will not automatically make you better at manufacturing or solve whatever troubles you are facing. There is some expertise in the creating of Standardized Work as well as the equally important Job Instruction forms or Work Standards. This post is mainly concerned with highlighting the differences between the types and elimination the misconception that Standardized Work is the only form you will find inside of Toyota. You won’t find the Standardized Work Chart outside of manufacturing either as other forms are used.