Example

The network in the figure is for a project in which the key resources is

engineers. The network has been evaluated on the assumption that an

unlimited number of engineers is available and the duration of the project is then $28$ days as shown.

Resource aggregation:

$1-$draw the histogram showing the demand for engineers:

Schedule the start of each activity if only $3$ engineers are available and

determine the effect on the project duration and draw $($the resource diagram vs duration$)$ knowing that when the engineers become $3$ the duration will increase

Assume in this case that no activity can be split.