A robot, on the other hand, is much more consistent and less tolerant of parts differences. As a result, engineers need to clearly define a range of part variances so the assembly system can identify acceptable parts. They may ultimately have to tighten parts specifications, or redesign the product and its constituent parts so it will be easier for a robot to assemble. This is an often underappreciated aspect to robotics-that it forces assemblers to clean up their act.

In some ways, this process is similar to that used in streamlining manual assembly. For example, reducing the number of parts in a product will cut costs and increase process reliability, regardless of the type of equipment used to assemble it. However, other guidelines are more specific to robots.

For example, unlike human assemblers, a single robot cannot hold a part in one hand and a tool in the other. Therefore, products should be designed so they can be assembled in layers from the bottom up, without having to be reoriented midway through their assembly-wasted motion that serves only to increase cycle times.

Similarly, because robots still cannot move with quite the same repeatability as dedicated, "hard" automation, it is a good idea if parts have self-aligning features, such as lips or chamfers, to help the robot insert them.

Throughout this process, operators should be consulted on the nuances of their work: how they identify good parts; what techniques they may use to facilitate assembly. Encouraging input from employees can provide the insight necessary to create an effective, total application.