Measurement and Metrics - Requirements Engineering and Management for Software Development Projects - page 146

analysis to uncover the reason behind the high percentage of time spent on
resolving the CRs. This metric helps us in understanding if the project effort is
wasted on resolving preventable CRs.

10.3.5 Schedule Metrics

Effort metrics tell us the impact on the cost and thereby on the profit. While effort
metrics are important for the organization, delivering the software, on schedule is
much more important for the customer. Not achieving the benchmark effort
metrics, would impact the cost and profit from the project but would not have
strategic impact. Not achieving accepted schedules may even cause the project to
be cancelled and thus has strategic impact on the organization. We compute the
below schedule metrics.

10.3.5.1 Overall Schedule Metric

Here we compute the schedule metric for the schedule of the completion of
requirements stage in the software development signified by the establishment of
URS and the SRS and subjecting them to the rigor of configuration management.
This metric is expressed as a percentage. The formula for deriving this metric is:

SMRE ¼ Number of calendar days actually taken Number of
calendar days scheduled Þ Number of calendar days scheduled 100

where SMRE is the Schedule Metric for Requirements Engineering
This metric is positive when we overshoot the schedule, that is, the delivery is
delayed

and negative when we beat the schedule and delivered before the

scheduled delivery date.
While there is no industry wide benchmark for this metric, any amount of delay
is frowned upon.
Another important question is which scheduled date is to be considered—is it
the original schedule or the amended schedule?
From the standpoint of organizational efficiency, we need to take the original
schedule into consideration. It may not always be to our liking. We may use the
amended schedule if we wish to present an attractive set of metrics.
The data for deriving this metric can be obtained from the project schedule and
the work register. This metric can be derived as soon as the URS and SRS are
subjected to the rigor of the configuration management.
This metric assists us in learning about our capability to meet the schedules and
improve them if necessary.