Problem abstraction

One of the most important soft skills in engineering design is the ability to carry out problem abstraction. In this step you will learn what it is and why it is such an important skill. First, let’s remind ourselves of the design brief that we looked at earlier:

Back to the design brief

When you developed the conceptual design of the wave-powered pump earlier, you started from this original design brief:

• Boats which are kept afloat throughout the year suffer from the ingress of water due to rain, high waves and the possible infiltration of water through the boat’s hull.
• Using a mains-powered pump is not possible in this case, while a battery-powered pump requires regular visits to replace or recharge the battery.
• The natural movement of the boat in the water due to waves can provide enough energy to pump water out of the boat if a suitable design can be developed.
• The solution should be simple, low cost and very reliable.

The brief required you to harness the kinetic energy of the boat’s motion and use it to drive a pumping device. It may not have been obvious that this brief is actually biased and proposes one specific solution to the problem, i.e. one based on harnessing wave power.

The proposed solution may have been the result of comprehensive research about sources of alternative energy. But it could have been based on one idea that came to the mind(s) of the person(s) who proposed the design task.

How do you develop the right solution?

So, do people who have boats really want this particular solution? Is it the best one? Careful consideration of the problem can lead to the conclusion that boat owners simply need a way of keeping their boats free from water, whether this is achieved by a pump driven by wave power, solar power or wind power. In fact, they may not need a pump at all if suitable methods can be found to keep water out of their boats in the first place.

Therefore, designers must make sure that they are really working to solve the correct problem. In this case, a small discussion with the person(s) who prepared the design brief may lead to the conclusion that any solution that can pump water out of a boat, regardless of how it works, is the real aim of the design task in this case.

Problem abstraction

This process of returning a problem to its root is called problem abstraction, and in many cases it can drastically reduce the complexity, cost and time needed to find a solution. In the water pumping example, the designer may now explore solutions that are based on powering a pump from wind or solar energy. This may, or may not, lead to a better solution, but at least you can be confident that you have explored all alternative concepts upon which the design of the product can be based. Below is a more abstract design brief for the water pumping problem:

• Boats which are kept afloat throughout the year suffer from the ingress of water due to rain, high waves and the possible infiltration of water through the boat’s hull.
• Using a mains-powered pump is not possible in this case, while a battery-powered pump requires regular visits to replace or recharge the battery.
• A suitable pump that does not require mains power or regular charging of batteries is required.
• The solution should be simple, low cost and very reliable.

Customer involvement in the solution

It is quite common for a customer to propose a solution in their design brief. But in many cases, this solution is not the best one, and abstraction of the problem can lead to a more abstract design brief that opens more opportunities. Only when customers insist that they want a design based on one particular solution should designers not use abstraction to find the root problem. In the end, problem abstraction is needed to avoid spending time and money creating a perfect solution to the wrong problem.