Creative Problem Solving

The root cause of many quality, manufacturing, and performance problems can be traced to two main causes: (1) undesirable interactions and (2) design complexity. Undesirable interactions occur when functional requirements become coupled in undesirable ways, such as when application of a vehicle’s brakes causes the vehicle to pull to the left or right. Similarly, complex part shapes, excessive part counts, hard to perform adjustments, many separate and/or different fasteners, hard to control processes, and randomness are all indications that the design is too complex. Often, hard to explain and/or seemingly intractable quality, manufacturing, and product performance problems can be solved in very creative ways by identifying the undesirable interactions that may be present and then generating redesign alternatives that “decouple” the interaction and simplify the design.

The basic problem solving process is shown in Fig. 1 below. This consultant has used this process to solve numerous problems. To illustrate the process, consider the simplified document transport system shown in Fig. 2. The drive motor for the design was selected based on drive torque measurements made on a prototype of the product. Subsequently, drive torque for production models was found to vary significantly from product to product and to be as much as four times the drive torque originally measured in the prototype. To correct the problem, tolerances on the sheet metal frame were tightened significantly and considerable effort was expended in working with the frame supplier to ensure close conformance to tolerance specifications. In addition, the bushings were hardened to guard against excessive wear. This associate was brought in when these measures did not help. Using the problem solving process of Fig. 1, this associate identified an undesirable interaction between the baffle plate and the way it is fastened to the side plates. Unless the baffle is perfectly made, which is not possible, the baffle either spreads the side plates apart or pulls them together when the screws are tightened. In either case, the shaft is loaded in bending creating excessive frictional drag. Once the undesirable interaction was recognized, this associate was able to propose a variety of redesigns that ranged from changing the fastener orientation to tighten in a less sensitive direction to eliminating the problem altogether using integral design. In addition to decoupling the undesirable interaction, all of the redesigns were significantly less complex.

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