| Posted by Ken Ramsley , Nov 14,2002,14:02 | Forum |
As the design process moves ahead there is almost always a conflict among the various needs of each parameter. Perhaps the stated goal is to create a full-sized SUV with a 100-mile-per-gallon fuel economy. But this can not be made with current technology, and in such a case the project goal will need to be adjusted to resolve the conflict among parameters by asking: What is 'enough fuel economy' for the product to still meet the basic intent? How small can this SUV become in order to help save on fuel? If the parameter of high fuel economy can be lowered enough, and the weight of the truck lowered as well, perhaps the conflict among parameters can be resolved.
A design project is considered to be over-constrained by its parameters when no plausible compromise is possible that will reach the intended overall objective... Some extreme examples: a sports car that can carry 75 passengers... a school bus that you can drive to the top of Mount Everest... a commuter helicopter that can be folded into a lunchbox... A 3D computer game that contains a complete model of the entire world.
Early in the design process, potential compromises must be floated to test whether or not the overall objective is plausible, and if this goal still seems attainable, then a more carefully worked-out proposal can be developed. But if no compromise seems to work (even through the hope of discovering new technology), then the overall project goal must be abandoned or severely amended, since the basic laws of logic and physics can not be successfully trampled.
Those who choose to continue the development project in the face of an unattainable goal may wind up creating something, and this result may actually have some utility in the real world. But the unintended gizmo will not match the original project intent, and its success or failure in the real world will be an unplanned random event, which, by shear serendipity, may turn into a success (but usually not).
Serendipity, by definition, is the exception rather than the rule and so it is almost always better (and cheaper, and less painful, and less disappointing) to end or severely amend a project before it goes wildly out of control, than it is to hope that lady luck will bail you out in the end.