Decision Thinking – its time is coming

I was trained as a mechanical engineer. I know how to model systems, take data and develop an understanding for physical things. Most (nearly all) technical university courses are about how to analyze things. In my case these were physical things, but my education could have been in any engineering discipline, in business or in the sciences, and the courses still would have been primarily “thing” focused.

In the 1980s I was teaching mechanical engineering design at a university and began to appreciate that things come into being through a process. My thinking moved from being thing focused to being process focused. Process thinking was not new to some fields. In fact, in engineering there are control processes, chemical processes, fluid thermal processes etc. But these are nothing but “process” things. What I became interested in was the process of developing these things.

In 1990 I began work on a text book for mechanical engineers so that they could study the process of how things mature from need to a final, working object. I agonized over the title as the term “process” was not really a part of the engineering lexicon except for process things. I finally chose the title “The Mechanical Design Process” and the book was published in 1992. This title turned out to be a good choice and the 4th edition of the book is out in January 2009.

When I began to research the design process in about 1984, my goal was to understand how objects evolve with eye toward developing methods and tools to better support this evolution. I don’t mean CAD and solid modeling tools as these are representation tools for what is being designed, not tools that actually support the design process. In fact, I have argued in a paper I wrote in 1990 that CAD can be detrimental to the design process ( Ullman and Wood, 1990). Since writing this paper, CAD has evolved into solid modeling which is much better, but the arguments in the paper still hold.

Anyway, I was especially interested in developing a tool that could record the evolution and rationale for product evolution. This design rationale system would be able to capture how a product came into being and could be reused, queried and vetted to form a permanent record of its birth, life and death. When I began, I focused on the evolution of the assemblies, parts, and features. I quickly realized that this wouldn’t work because these things evolve during the design process and thus, focusing on them missed all the birthing – all the interesting, creative engineering.

My thinking turned to capturing the process through which things evolved. Process thinking encapsulates thing thinking as the process is about the evolving things. This shift in my thinking coincided with the text book mentioned above. However, it became evident by the mid 90s that process thinking, although much better than thing thinking, was not the best way to develop a design rationale system. What became evident was that decisions are the punctuation marks in the process and that my approach had to make yet another shift, one to decision thinking.

Thus, by the late 1990s my thinking had matured from thing, to process, to the decisions made during the process to develop things. Specifically, I wanted to understand and support the decision-making process. My research showed that on macro level, decisions were made at gates (in a stage-gate process) a countably few times during the evolution of a product. On the micro level – the cognitive level - they occur about 1 decision per minute (see Stauffer,and Ullman 1991). Somewhere between these extremes there is much need for decision making support.

Before we go on, a definition of decision thinking - decision thinking is focusing on the decision-making process used during technical or business development. “Focusing” implies understanding and supporting individual decision makers and teams of people making decisions when information is incomplete, evolving and conflicting so that the decisions are robust.

I am not alone in this evolution in thinking. First, when I chose the tile “The Mechanical Design Process”, the word “process” was problematic as it was not commonly used in industry. Now, the product development industry makes good use of process thinking. Then, when I started talking about decision thinking in the late 1990s few in industry knew what I was talking about. Now there is much evidence that companies and the government are beginning to realize the importance of decision-making in their processes. My evidence for this is not firm, but many of my contacts seem to understand what I am talking about and few did five years ago, and the number of hits on the Robust Decisions web site continues to climb. Their thinking is maturing through the process to the decisions made during the process.

Second, the CAD industry matured into PLM (Product Lifecycle Management) during the 1990s. Where CAD and solid modeling is about things, PLM is about processes that manage things and document things. I have tried to interest the PLM vendors in decision thinking for about eight years. Initially they told me there was no customer pull (see the previous paragraph). Recently, I have gotten their attention. Now that they have the process under control, they too are maturing toward decision thinking.

Ullman, D.G., S. Wood, D. Craig, "The Importance of Drawing in the Mechanical Design Process," Computers and Graphics, Special Issue on Features and Geometric Reasoning, Vol. 14, No. 2, 1990, pp. 263-274.

Stauffer, L.A., D.G. Ullman, "Fundamental Processes of Mechanical Designers Based on Empirical Data," Journal of Engineering Design, Vol. 2, No. 2, 1991, pp. 113-126.