Involves displaying all the activities involved in a particular project in diagrammatical form, so as to communicate exactly when the resources are required and for how long. It allows a business to estimate the shortest possible time in which a project can be completed and identifies those activities that must be completed on time in order to avoid delaying the entire project (ie the activities that form part of the critical path). It is used for complex projects such as building and construction, as well as marketing plans involving research, advertising and test marketing. Besides being used to estimate and minimise project completion time, it can be used to cost and select projects to undertake, and can help to plan, organise, prioritise and monitor and control the use of resources. Communicating the expected finish times of each activity to employees can also help managers to motivate staff – people can monitor their performance and assess how they are doing against the targets set. It is used for complex projects such as building and construction, as well as marketing plans involving research, advertising and test marketing.