I have to admit I got a few more responses than expected from my reply on the blog. It got me very curious about the subject of Standard Work. Standard Work kaizen was an integral element to my ‘Lean Upbrining’. I have worked with several Sensei from Shingijitsu and my learning is based on what they taught in regards to Standard Work. So realize that the following commentary is based on my view and the method of implementing Standard Work can and will vary.

In my interest I started looking into the Literature that I use most for reference. That is ‘The Toyota Way’ and ‘Gemba Kaizen’ and what I found was surprising. Although both books talk about Lean Philosophy neither of them really get to the ‘down and dirty’ of how to capture Standard Work. So if you are interested please follow along. Note: hopefully the documents will be attached in my second response by now.

Scenario:

You have an operator feeding an operation with the following step:

1.  Operator reaches for blank

2.  Operator loads machine

3.  Operator cycles machine

4.  Operator removes part

5.  Operator returns to start next cycle

The first step in the process is to collect the data (in this case time) in elemental steps. Elements or elemental steps are the smallest recognizable steps in the process (as shown above). Generally you want to get somewhat detailed in the steps as later on you may determine ways to simplify or eliminate steps. They also come in handy when performing Heijunka (level loading) in cells where work share is possible. I use the Observation Sheet and a stopwatch to collect this data. Stopwatches that can collect 100 or more times and then recall the data are best.

I try to get at least 10 full cycles (by element) completed during my Time Study. Another good idea if you have access to a video camera is to tape the operation so that I can stop and review as needed. Most of the columns are self-explanatory but just to be clear the elemental description should explain what the operator is doing and the ‘Break’ should be the visible separation between one element and the next. So the above would look like this:

Elemental Description Break

1. Get Blank touch part

2. Load Machine release part

3. Cycle Machine touch switch

4. Remove part place part

5. Return stationary position

The ‘LR’ on the document is Lowest Repeatable meaning that as you scan across the elemental row what is the lowest value that is repeatable. This is the method that I was taught to determine each element. However in experience I have learned that this can tend to be the perfect scenario. Therefore I have added the column “AVG” which should be the average of the elemental row. I compare these two numbers to look for variability. This is done for each elemental row. The overall Cycle Time are then calculated along the bottom (with averages as well) and then compared. The Lowest Repeatable Total Cycle Time should be the target you are shooting for as well. In most cases the sum of the Lowest Repeatable Elements is going to be lower than the Lowest Repeatable Overall Cycle Time. Elemental times need to be moved up to match the Cycle Time – this might take some judgment on your part from observing the Operator.

The Standard Work Combination Sheet (SWCS) is difficult to explain in written word so I am going to skip over it and move to the Process Variation Analysis Sheet. There are 40 iterations across the bottom and the left side is given for Time. Depending on the total Cycle Time the left side can be different; most of the time I use 3, 5 or 10 seconds. The process for filling out this sheet usually works better if you have two people. One person will use the stopwatch and call out the times (again full cycle times rather than elemental times) and the other person will put a dot corresponding with the time and iteration. Once the sheet is completed (40 cycles) simply connect the dots.

So what are we looking for? If the line is basically straight and the average Cycle Times match up with what we have from the Observation Sheet then we are good to go. There will probably be a Blue Moon in the sky that night too. What I usually see is that 80% of the times are within a 10%-20% range and the other 20% of the time are off because we have not included things like having to get another stack of parts or quality checks. Some of the variation can be dealt with by for instance having a Water Strider route that reloads the parts for the operator but if there is not a simple fix you will need to find a way to incorporate the time into the Standard Work to allow the Operator to meet their Cycle Time.

The Standard Work Layout is a visual depiction of the work area. It is pretty straight forward but one note I will add is try to keep the process steps from the SWCS and Observation Sheet the same as the ones you will be putting on the Layout. What this does for you is you have the times from the SWCS and they are visually depicted on the Layout.

I know this one is lengthy but I ended up getting A LOT of questions regarding the post and thought it might be worthwhile to post the information.

Randy