Explain the customer problem arrival curve in terms of customer usage of the product and fixes.
Answer: Customer problem arrival rate is directly related to the customer problem discovery rate. The rate of customer problem discovery is proportional to the amount of usage the software is experiencing.
For example, a new software that has not been run often will not have much usage-time and the discovery of software problems will be relatively low. As the usage-time increases, the discovery of defects increases accordingly. After a period of time, the discovered problems will be fixed and all the major areas of software would have been exercised. Thus the discovery rate of defects will once again become low after a period of heavy usage and problem fixes.
The graphical curve of this rise of problem discovery and problem arrival on the Y-axis with increase in usage-time (on the X-axis) followed by a gradual decrease of problem discovery (the Y-axis) may be modeled with a Rayleigh curve.