Technical Performance Measures

Once your technical performance measures (TPMs) have been established, they becomes the key to understanding whether or not our design meets or exceeds the requirements, and competing products. Setting the TPMs or ‘metrics’ allows us to compare designs against a common scale. It’s important to make sure that your technical performance measures are limited to the key needs of your design.

Example applications

Finding the right metrics to judge your performance is key to a successful project. It is also important to explore exactly what the metric means. For example, if your client wants you to design a ‘fast’ car, does that mean more engine power (Watts), more torque (Newton-metres), top engine speed (RPMs), lightweight (kg) or reduction of the drag co-efficient. Exploring which TPMs you choose to measure your project will completely change the direction of your optimisation.

Steps

Take your customer requirements, and convert them into a manageable number of design requirements:

  1. Design requirements should be neutral and measurable:
    • CR: faster car; DR: speed, engine torque, mass
    • CH: cheap; DR: cost of materials, fuel consumption, ongoing cost, capital cost, etc
  2. With your design requirements, establish the metrics that each DR can be measured against (each DR could probably be measured at least 5 ways)
  3. Establish whether the desired direction of the TPM is to increase, decrease or optimise the metric value, and set any minimum/maximum requirement or benchmark.
  4. Take your expanded list of metrics, and decide on a subset of TPMs to measure your project again (at least one per requirement is a good guide)

Hints

  • Listing all the ways that a customer requirement could be measured will help you to be explicit about the project’s requirements
  • Explore the TPMs with your client - get them to help you identify exactly what they mean.

Core resources

  • Blanchard, B.S., W.J. Fabrycky, Systems Engineering and Analysis, Fifth ed. Pearson, New Jersey, 2011. Chapter 3.6, pp96-100 [PDF, 5 pages]\ Glossary for that reading: MTBF is Mean Time Before Failure, MTBM is Mean Time Before Maintenance, LCC is Life-Cycle Cost.
  • INCOSE Technical Measurement Guide [PDF, 65 pages, read particularly 3.2.3 (pp10-11) and Figure 3.3 (p16){: .link-ext target=”_blank” } for examples]\

Updated:  12 Mar 2018/ Responsible Officer:  Head of School/ Page Contact:  Page Contact