One of our readers Harish asked:
Recently I have come across different types of standardized work in two or three places during my research. They are Type 1, 2 and 3. Can you please throw some light on this?
While the concept was not new this “type 1, 2, 3” terminology was new to me also until about two years ago. Checking with several people who left Toyota as recently as the year 2000, they were also not aware of the “types 1, 2 and 3” classification. None of my Japanese sources reference this either.
My guess is that this is a fairly recent addition to TPS terminology or possibly something coined in English to specifically explain the variants of standardized work to overseas Toyota plans.
Instead of 1, 2 and 3 it is easier to think of them as repetitive, variable cycle and long cycle.
The first type is the garden variety standard work which is the same repetitive cycle for every product and is most commonly seen on an assembly line or u-shaped machining cell producing a well-defined product family. The work process is designed to keep the fluctuation of operator cycle time above or below takt time to a minimum.
This is the type of standardized work that most people encounter when studying or implementing lean manufacturing. Type 1 is relatively easy to understand, to use as the basis of training and to manage.
When observing type 1 standard work being performed, one would expect to see the same work sequence, cycle times neatly balanced to just below takt time and the standard work in process quantities maintained.
The second type is most often seen as having a short but variable cycle, most often seen on a mixed model moving assembly line. Instead of producing a repetitive series of product AAAAAAAA all day the mixed line may produce the pattern BACBACBC.
There may be visible differences between each “A” product but in terms of work sequence and time there is no difference, while each A, B and C models may cause waiting time or prevent the operator from meeting takt time due to work content. However within the repeating section of the pattern the standardized work can be followed.
When observing type 2 standard work being performed, one would expect to see the same elements of standard work repeating every time the same products appeared in the pattern.
The third type of standard work is referred to as long cycle and refers to work that repeats but includes variable occasional work such as conveyance, changeovers or even minor and brief relief work for another team member nearby. The individual work sequence and takt time are fixed as with any type of standard work, but the variable nature of container removal and conveyance, tool changes and so forth means the content of the work can be variable.
The preferred approach is to isolate as much of this variable work as possible in order to assign one support position that handles the variation while allowing others to work closely to type 1 or type 2 standard work. Overall this allows everyone be more productive and also highlights all of the wastes and elements of variation in the one support position.
The logical extension of this is to have water spiders, team leaders and group leaders who build their standard work around mostly variable work. This is the “standardization of indirect work” which is a frontier area for many companies well advanced in the typical lean manufacturing shop floor practices.
When observing type 3 standard work being performed, one would expect to see the repetitive elements of standard work being performed with occasional interruptions that seem to totally disrupt the cycle but in fact return peacefully to the beginning of the albeit longer cycle.
This separation of standardized work into the three types of repetitive single cycle, variable cycle and long cycle helps us remove the excuses that “we don’t make the same product over and over again” or “we have so many variants” or even “my work content is variable.”
In fact the “long cycle” of type 3 standard work is often extrapolated to mean “repeats across a period of days or weeks” in order to create daily management routines or what is sometimes called leader standard work.
No matter how creative, unique or different we are, everyone follows the type 3 standard work of being born, living and dying. The exact work content within each our cycles varies, but we are blessed to be here and to be able to practice kaizen against this long cycle standard work.