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Last edited 09 Sep 2016

Commissioning v testing

Contents

[edit] Introduction

It is important for the project manager to understand the differences between the terms testing, commissioning and performance testing, and to ensure that the programme has sufficient time within it to enable these activities to be undertaken. Unfortunately, with this stage of the project being so close to handover, there is often pressure to gain time by shortening the testing, commissioning and performance/environmental testing programme. This should be strongly resisted. Rarely, if ever, after the project will such an opportunity exist to fully test the services to ensure that they work individually, as a system, and, that they work under part-load and full-load conditions. Many problems with respect to the under-performance of services within an occupied building can be related back to either insufficient quality in the testing and commissioning, or, insufficient time to test and commission.

It should also be borne in mind that various statutory services will need to be demonstrated to site inspectors, and insurers. Time should be allowed for within the programme since these activities are often taken as separate tests after the main commissioning has been undertaken.

[edit] Testing

During services installation various tests will be undertaken known as “static testing”. This testing is normally undertaken to prove the quality and workmanship of the installation. Such work is undertaken before a certificate is issued to “enliven” (i.e. to make live) services whether electrically or otherwise. Examples of this sort of testing are:

  • Pressure testing ductwork and pipework.
  • Undertaking resistance checks on cabling.

[edit] Commissioning

Upon completion of static testing, dynamic testing can be undertaken, this is 'commissioning'. Commissioning is carried out to prove that the systems operate and perform to the design intent and specification. This work is extensive and normally commences by issuing a certificate permitting the installation to be made “live”, i.e. electrical power on. After initial tests of phase rotation on the electrical installation and checking fan/pump rotation (in the correct direction), the more recognised commissioning activities of balancing, volume testing, load bank testing, etc. begin.

[edit] Performance testing

Upon completion of the commissioning, performance testing can begin. Some may not distinguish between commissioning and performance testing. However, for programming purposes it is worth distinguishing between commissioning plant as individual systems and undertaking tests of all plant systems together, known as performance testing, (and including environmental testing). Sometimes this performance testing is undertaken once the client has occupied the facility, e.g. for the first year because systems are dependent upon different weather conditions. In such cases, arrangements for contractor access after handover to fine-tune the services in response to changing demands must be made. However, for some facilities it may be necessary to simulate the various conditions expected to prove that the plant systems and controls operate prior to handover, e.g. computer rooms..


This text in based on an extract from PROJECT MANAGEMENT, by Eric Stokes and Saleem Akram. The original manual was published in 2008. It was developed within the scope of the LdV program, project number: 2009-1-PL1-LEO05-05016 entitled “Common Learning Outcomes for European Managers in Construction”. It is reproduced here in a slightly modified form with the kind permission of the Chartered Institute of Building.

--CIOB

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