Project Requirements

Measuring Requirements

As a practical matter, it is typically useful to have some concept of the volume of the requirements for a particular software product. This number is useful in evaluating the size of a change in requirements, in estimating the cost of a development or maintenance task, or simply in using it as the denominator in other measurements (see Table 9.1).

Property Measure
Speed
  • Processed transactions/second
  • User/Event response time
  • Screen refresh time
Size
  • K Bytes
  • Number of RAM chips
Ease of use
  • Training time
  • Number of help frames
Reliability
  • Mean time to failure
  • Probability of unavailability
  • Rate of failure occurrence
  • Availability
Robustness
  • Time to restart after failure
  • Percentage of events causing failure
  • Probability of data corruption on failure
Portability
  • Percentage of target dependent statements
  • Number of target systems

Table 9.1: Measuring Requirements