The Five Part Solution


My introduction to the subject of Part Count Reduction came about as an observation of the results of a Design Project in my sophomore year of college.  I’ve come to refer to the anecdote as “The Five Part Solution” which might have been long forgotten had the saga not come with an accompanying lesson in humility.

The Design Project was a first instance of being challenged for an original engineering solution and I recall “enthusiastically” devoting several weekends to research and then to developing a concept for my proposal.  With some degree of pride I completed my design, an electro-mechanical masterpiece replete with springs, hinges, micro-switches, transformers, etc.  Accompanying my submission was a full set of Assembly & Detail drawings of each part and included a 40 (or perhaps 50) piece Parts List.

On entering the classroom to submit my proposal I noted that a group of students were chatting excitedly in a corner of the room.  Their attention had been drawn by another student who was busily demonstrating the operation of his design proposal on a mock-up he’d constructed of wood in his garage.  His design was a stunning contrast to my own elaborate proposal as it contained only five mechanical members and required no external power to operate; the Five Part Solution.

 I still remember being struck by the elegant simplicity of the Five Part Solution which has garnered even greater appreciation as I’ve grown to understand the full impact of engineering decisions on the cost of a product. Had my product design competed with the Five Part Solution in the “Real World” one manufacturer (his) would hold a significant price advantage and so enjoyed much greater success in the marketplace.

The story of the Five Part Solution demonstrates why Castings and in particular Investment Castings are such an effective manufacturing method.  Castings offer a unique capability to combine multiple features into a unitized structure that reduces the total part count of an assembly and improves the overall affordability of an engineered product.  We encourage that Engineers take advantage of the opportunity that castings present and to write their own Five Part Solution.