Plan, Do, Check, Act (PDCA)

Plan, Do, Check, Act (PDCA) is a model that is used to assist the control and continual improvement of processes and projects. It has been used in construction project management as a means of balancing the systems and behavioural aspects of management and health and safety. Its cyclic approach allows for the constant updating of health and safety measure ultimately leading to a safer working environment.

PDCA was popularised by W. Edwards Deming, a leading figure in modern quality control processes and procedures. Deming intended that PDCA should be used when developing a new or improved process, product or service; when implementing changes; when defining a repetitive work process, and so on.

It is made up of the following stages:

Plan: Assess a current or new process and how improvements could be made.
Do: Test small changes as part of a limited study to assess their effectiveness.
Check: Gather and analyse the test results, compare them with the expected outcomes and identify what has been learnt.
Act: Take action according to the lesson learned in the ‘Check’ step.

In some iterations of PDCA, the fourth step ‘Act’ is replaced with ‘Adjust’. This is often used when the PDCA process has been run several times and enough information has been accumulated for it to have been adopted as a new ‘standard’. ‘Adjust’ allows for continual monitoring of the process after changes have been made, with small improvements as and when appropriate, creating a cycle of continuous improvement.