Putnam-Norden-Rayleigh Curve

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In the study of software project scheduling, the Putnam-Norden-Rayleigh Curve, also known as the PNR Curve, is a graphical curve derived from a mathematical equation that indicated the relationship between applied effort and delivery time in relation to a software project. A PNR curve can be used to determine the least cost time for delivery to up to the limit tmin, the absolute minimal amount of time required to complete the project no matter how many human resources are added. The PNR curve was used to derive the Software equation.[1]

[edit] Equation

The following equation shows the relationship of project effort as a function of project delivery time.

E_a=m \left ( \frac{{t_d}^4}{{t_a}^4}\right )

Where

  • Ea=Effort in person months
  • td=The nominal delivery time for the schedule
  • ta=Actual delivery time desired

[edit] See also

[edit] References

  1. ^ Pressman, Roger S. [1982] (2005). Software Engineering - A Practitioner's Approach, 6th, Newyork, NY: McGraw-Hill, 678-679. ISBN 0-07-285318-2. 
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