Waste of Overprocessing
As with most other types of inefficiencies, some waste of overprocessing will be easily identifiable, while others will not be. An in-depth look at current processes should reveal where the improvement opportunities exist, although they may not be quick to eliminate. The three main things to consider with waste of processing are whether or not the work is actually necessary, if it adds value to the product and if there is a better method in which to preform the work.
Necessary Work/Value Added
The first considerations when looking to eliminate waste of overprocessing are whether or not the work is actually necessary and/or if it adds value to the final product. Some adjustments or trimming may be done to a part, but is it actually required? Does it increase the value of the product or improve the function of it? Does it make the product more appealing to the consumer? For example, in the automotive industry, many parts are visible in the car, however the entire part may not be visible.
In the case of a plastic part, spending time trimming material in areas of the part that will not be seen in the vehicle is a waste (considering the part still functions as required) and does not add value to the part. Areas like this need to be reviewed and a decision must be made on whether or not the work is actually necessary. A de-burring process may fall into this category if the area will not be visible and the part will function as required without the de-burring. Are there any other steps in your processes that aren't required?
When focusing on eliminating waste of overprocessing, you must always look for better methods to produce your product or perform your service. If a machine is running a staking process and holds the parts for 10 seconds, can you get the same result if the part is held for only 9 seconds? When molding product in a 150 tonne machine, can you get the same results out of a 100 tonne machine? Many of the fixes in this area may not be easy or cheap, but eliminating the overprocessing can save you money in the long run by increasing throughput.
A one second reduction in cycle time (from a 10 second cycle time to 9 seconds) will increase throughput in 8 hours by 320 parts. Over the course of 250 working days it would net an extra 80,000 parts in a year. This is a one second cycle time reduction on one part. How many other seconds can you shave off your other processes.
The same works for improved methods. By spending money up front and improving processes (or automating some processes), you may be able to run your operations with less manpower. In the end, when trying to reduce or eliminate waste of overprocessing,if there's a better more efficient method for getting the same or better results, investigate it and implement it if it's feasible.