Reading time ( words)
“Why do we do it that way?” “Because we always have.”
Those can be some of the most dreaded words on the manufacturing floor. It means that someone decided at one point to do things a certain way, and you don’t know whether it’s a critical aspect of the assembly process, or just another roadblock to improvement. Knowledge is a significant asset to manufacturing; it is critical for manufacturing a reliable product, and effectively managing tribal knowledge is more important than ever as people change roles often. Not only does it require effort to bring new people up to speed, but it is also difficult for those who are moving on to convey everything they’ve done (“Why did they make that change?”).
This tribal knowledge concerning the how and why of an assembly process is not unique to one group; it includes knowledge held by all roles in manufacturing, such as assemblers, engineers, and quality assurance. It can be an assembly-specific item about target conditions, methods that make the process easier or more consistent, or what tooling to use and how. Even documented requirements can be affected, with variations in the interpretation of standards or engineering requirements. Consistency in the manufacturing process is key to identifying problems, whether it’s a rash of acceptance test failures or long-term reliability trends. The fewer variables that need to be considered, the more confident one can be about impacts of those variables. Although it is desirable to maximize flexibility for the process, it must be done without compromising consistency and quality, which lead to reliability.
What is Your Process?
Most groups use a variety of methods to capture tribal information. Work instructions can be the most obvious and are often used as corrective action when problems surface. Adding detailed instructions can be helpful, but too much can have the opposite effect, as an assembler may stop reading when they think they get the point. Pictures and videos can convey a great amount of information quickly, but key points may need to be emphasized, and changes to the design may drive the need for frequent updates.
In many cases, the buddy system is often used because it’s easy; the new person is taught by the old. This method is the definition of tribal knowledge and has the obvious disadvantages of losing information in the relay, not to mention that this is also an effective method of passing on bad habits along with good.
Training programs require extra effort to develop and are best for standard processes and procedures. The more formal the training, the more difficult it typically is to maintain. Less formal training (on-the-job training or training checklists) can be much more flexible, but they are also more likely to deteriorate or not be used.
Mistake-proofing is always a good option, which essentially builds the knowledge into the process. There needs to be a way to keep changes from being made when the reason for the process isn’t clear.
To read this entire article, which appeared in the July 2021 issue of SMT007 Magazine, click here.