You can’t plan a schedule or estimate cost without knowing how much labor is required to make a product. This data has traditionally been collected with clipboards and stopwatches. The selected time is simply the average of the data sample. From a distance this works well — some production runs will be faster, others slower, but that middle area gives a fair representation. The standard deviation is the extent of variances inside a data sample, these variances can shed a tremendous amount of light on the troubles your operators face.
Operators are fastening a housing together, and to do so there are 3 steps:
- Install clip-nuts around the edges of a housing.
- Peel weather stripping, apply over edges of housing.
- Secure cover panel with 8 fasteners.
The production run requires only 7 units, their production times are shown below:
On average, it takes 7.35 minutes to build one of these units with a standard deviation of 0.8 minutes (or 11%, 0.8/7.35). This deviation might not seem too bad, and there is a great chance that the manufacturer wouldn’t think twice about it. However, when we analyze it further by looking at each step, we find that Step 1’s deviation is 13%, Step 2 is 15%, and Step 3 is 23%.
In my experience as a Manufacturing Engineer, 23% deviation deserves a closer look. Watching operators build the unit in person, I might see that they frequently have to re-tap the nuts, or the fasteners strip, or that the drill bit isn’t magnetic and the operators struggle holding the fastener to the bit. Each of those problems are easy to fix, and by doing so I am now ultimately reducing the labor of a heavily wasteful step.
Simplify Data Collection
The above example is not at all far fetched, and I’m sure any of you reading would find a similar example in your production facility. Collecting data is a laborious task, and sometimes it isn’t worth the upfront cost to reduce the production labor cost. Imagine if the data collection, and analysis was done automatically? How much more effective would your continuous improvement projects be? Scout System’s electronic work instruction software (Compass), does exactly that. Operators have step-by-step instructions that guide them through their build, while collecting tremendous production data. In a matter of seconds, reports can be run to identify which units are causing the greatest amount of waste, and that can be broken down to the exact area for your review.