Sensitivity study

Sensitivity study: what for?

What is your situation?

  • I am participating in the design of an underwater mechanical and articulated system, which has to meet particular performance specifications. How can I find the best compromise between reducing the production cost and high performance?
  • Starting from a preliminary design project, I need to optimise the configuration of my future manufacturing factory to get the best efficiency possible and respect environmental constraints. How can I do that?
  • The control system of my industrial gas production installation is updated and I would like to take advantage of the opportunity to enhance the gas quality control and increase production by 2%. What is the correct approach?

In each of these cases, a sensitivity study is a great way to help you make the right decision.

What is a sensitivity study?

As its name says, a sensitivity study is a manner to quantify the sensitivity of a quantity to the variations of one of the system’s settings. For instance, we can study how the input temperature of an industrial process for a gas production affects the pureness of gas produced.

To achieve this task, we usually use simulations, choosing scenarios carefully in order to accurately determine the influence of each parameter studied. Thanks to simulation, we can explore a lot of configurations, of which some would be impossible to reproduce with real tests.

A sensitivity study can also be achieved by analysing data from measurements, when the system’s model is unknown. In that situation, the study will give valuable pieces of information to model the system.

Sensitivity analysis distinguishes the action of each parameter individually and graphically represents results, in order to sort parameters. Nowadays, the generation of a study report can be entirely automated thanks to simulation tools and document generation. Then, the engineer supervising the study will write down his conclusions taking his knowledge of the system and a detailed analysis of whole results into account.

After a sensitivity study and according to the problematic, the designer will be able to:

  • find a good compromise between several technical solutions (sensors or actuator choice for instance)
  • decide which parameters need to be changed first so as to modify the system’s behavior
  • quantify external disturbance influence and eventually taking it in account for the control system
  • specify his control issue in a smart way