Set Based Design

28 July, 2014

As a Project Manager, you will be expected to make decisions and there is often the temptation to make a decision before all the facts are in, in order to appear decisive. Indeed, there are people who argue that it is often better to make the wrong decision than not to make a decision at all. But is this the right approach?

Certainly advocates of Lean Principles will disagree. They argue that choosing between alterative solutions too soon can cause serious problems. Instead, they advise Project Managers to develop the alternatives further. Some will prove unsuitable on closer inspection and these may then be safely discarded. For instance, they might not satisfy the full set of requirements, or simply be too expensive to be viable. However, others may survive early investigation and we are advised to present these alternatives to the customer. Often, this approach leads to the customer selecting the best bits of each alternative and creating a novel hybrid solution – a solution that would not have occurred to the project team if the alternatives were discarded early.

Related to this recommendation is the notion of Set-based Design. This is an approach where you design based on known constraints, rather than on assumptions. A great example of this approach is seen in car design. Car designers do not rush to their drawing boards when asked to design the next generation sports car, or family saloon. Instead they march off to the product planning people and try to establish what chassis will be used for this new model, what crash structure, what engines, what suspension and what wheels will be available. They will need to know how many passengers to carry and what luggage space to provide.

Essentially they will identify the “hard points” of the design – what components will their body shape have to cover? If that was not enough, modern car stylists have to contend with a myriad of regulations concerning pedestrian safety – so no protrusions that would hurt a person on impact. Then of course, they have to be aware of aerodynamic efficiency and ease of repair.

Until all the constraints are known, there is little point in putting great effort into the styling. However, if the style is agreed and changes are made afterwards, the results can be awkward, to say the least. Designer Harris Mann produced this sketch when he worked in British Leyland:

However, senior management decided late in the day that they wanted to use an existing heater assembly and provide a larger capacity engine option. These new requirements meant that the scuttle line (the bottom of the windscreen) had to be raised by four inches. Mann’s original shape was forced to morph into this:

Project Managers are supposed to plan their work and then work their plan. However, there needs to be a certain amount of clarity before a project gets to the planning phase. If alternative solutions are out there, then a feasibility study should precede the project. Similarly, if the requirements have not been fully identified then we run the risk of designing something that does not meet customer expectations.

It is instructive for Project Managers to take a more active approach to Project Scope Management. When working in the Collect Requirements process, we should be aware that finding out what the customer wants is only one part of the task – a non-trivial one, granted - but another, vital outcome of this process is finding out what we need to know about the product, service and result in order to produce it.

With this mind-set, the “constraints” section of the Project Scope Statement suddenly has a larger purpose than the project management triple constraint. We need to include the constraints that our team will have to accommodate – for example, memory restrictions on embedded software projects, the need to provide a USB interface to an electronic device and, of course, the hard points of a car. Some of our technical constraints will have to be included in our quality constraints – what legislation will we have to conform to?

The adoption of Set-based Design will influence the way you explore requirements and provide a different perspective on constraints. It will also inform your list of assumptions because, if you cannot determine particular constraints, then you will have no choice but to make certain assumptions. However, as the Austin Allegro example shows, assumptions should also be filed as risks!

Velopi’s project management training courses cover project scope management. If this area is intriguing for you, you might consider one of our project management certification courses that are held in Dublin, Cork, Limerick and Galway. Find out more by visiting our training page or by contacting us directly.

By Velopi Seamus Collins

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