User-Centred Requirements Handbook |
It is often helpful to develop possible system concepts with a parallel process in which several different designers work out possible designs. The aim is to develop and evaluate different system ideas before settling on a single approach as a basis for the system.
In parallel design it is important to have the designers working independently, since the goal is to generate as much diversity as possible. Therefore the designers should not discuss their designs with each other until after they have produced their draft design concepts.
When designers have completed their designs, it is likely that they will have approached the problem in radically different ways that will give rise to different user systems. It is then possible to combine designs and take the best features from each.
It is important to employ parallel design for novel systems where they is no established guidelines for how best the system should operate.
Although parallel design might at first seem like an expensive approach, since many ideas are generated without implementing them, it is a very cheap way of exploring the range of possible system concepts and selecting the probable optimum.
Benefits
• Allows a range of ideas to be generated quickly and cost effectively.
• Parallel nature of the approach allows several approaches to be explored at the same time, thus compressing the concept development schedule.
• The concepts generated can often be combined so that the final system benefits from all ideas proposed.
• Only minimal resources and materials are required to convey product feel.
• The technique can be utilised by those with little or no human factors expertise.
Limitations
• Requires a number of design team members to be available at the same time to produce system concepts.
• Requires a lot of time over a short period for the design work to be carried out.
• Time is also needed to compare parallel design outputs properly so that the benefits of each approach are obtained.
What you need
The method requires design team members to be available concurrently in order to carry out design work in parallel. Briefing notes are also needed to make sure that the designers are given the same information are start the design from the same starting point.
Process
The following procedure may be adopted for implementing this method:
1. Define clearly the boundaries for the parallel design i.e. goal of system, tasks that it should support, user characteristics, etc.
2. If possible agree on the format that the design will be produced in, e.g. on paper, in software.
3. If design teams rather than individuals are being used, select groups that have roughly equivalent skills.
4. Set a clear time limit on the design phase.
5. Agree on the criteria by which the designs will be assessed.
6. Allow sufficient time to carry out a fair comparison of the designs produced.
7. Discuss each design separately and then discuss how different aspects of the designs may be combined.
Practical guidelines
• Make sure that all the design teams are given the same information before starting the design activity.
• Decide beforehand how much time to allocate to the design work. However if one team completes their work first be flexible in allowing others to come to their conclusions.
• Allow design teams to use whatever media they prefer in order to present their designs.
Further information
Nielsen (1993)