Page 222 - DCAP304_DCAP515_SOFTWARE_PROJECT_MANAGEMENT

Software Project Management

Notes  By excessive use of resources are we completing this activity more quickly than necessary
in terms of the overall project duration? Such an activity is not likely to be on the critical
path.
These questions will be answered later in the resource modeling process, specifically during the
resource leveling and smoothing stage.

Resource Aggregation

Resource aggregation, or resource loading, is simply the summation, on a period-by-period
basis, of the resources required to complete all activities based on the resource allocation carried
out in the previous stage. The results are usually shown graphically as a histogram. Such
aggregation may be done on an hourly, daily, or weekly basis, depending on the time unit used
to allocate resources. When a bar chart is used as the planning tool, the resource aggregation is
fairly simple and straightforward. For a given bar chart, there is a unique resource unit aggregation
chart which can be drawn underneath the bar chart. However, a separate graph will be required
for each resource unit. An example is shown in Figure 11.2 below, where, for a particular
resource, the required resource units for each time period are annotated on the bar chart. The
total number of resource units for each time period can then be summed and a resource aggregation
or load chart can be produced.

Figure 11.2: Resource Unit Aggregation Chart Derived from a Bar

However, when a network is used for planning, the resource aggregation procedure is not so
simple or straightforward. As the network is not drawn to a time-scale, there is not a direct link
between the network and the demand for resources. Therefore, a schedule must be prepared
which tabulates activities in terms of time. However, this highlights another difficulty, namely

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