Design Rationale

The topic of today’s post is Design Rationale. If you’re not yet familiar with this multidisciplinary concept, we’re not surprised. It’s a super specific framework that is often used in computer science, mechanical engineering, mechanical design, and several other areas of design and engineering. It is concerned with the explanation, often in the form of a document, of the set of decisions made when planning a system.

This concept is extremely important to any aspiring designer as its mastery will ensure well structured and objective results. It can be classified into different categories:

  • Process-based: In this type of design rationale, the structure is conducted by the necessary processes.
  •  Argumentation-based: As the name indicates, the argument and counter-argument is the pillar of this category
  • History-based: Here the design rationale is described as it happens.
  • Active document-based: In this category, the rationale is made before starting the decision. As the design process occurs, an algorithm checks decision against the pre-made rationale and if they differ, suggests a change.
  • Device-based: The model drives the rationale.

Further categories exist but are beyond the scope of this article. Of particular relevance are the argumentation and process-based types. These are, in our opinion, the most efficient and used methods of organization. Models such as the IBIS, the Toulmin model, and others, fall under the umbrella of argumentation-based design rationale.

The Design Rationale is often expressed in documents, as for example Ethereum, the cryptocurrency, has done. As you probably can tell by now, this framework is particularly popular with open source computer science projects, as it sets the standard for outside participants who may not have the required vision to maintain the project in its intended course.

This framework is attributed to the work of Stephen Toulmin, though only in the 70’s did it start to be formalized by other colleagues. It has since gained notoriety in the fields of computation and computer sciences.

As a final note, we will leave the following papers and books as recommendation for prospective design students:

If you have any further bibliographical suggestions, please let us know!