Staffing Software Maintenance and Support Projects

In the past decade outsourcing a software system´s support and maintenance has become relatively common across most organizations. In this paper we consider a few issues governing the staffing of support and maintenance projects from the perspective of the software service provider. Though queueing models have been used for the estimation of staffing requirements and control in the past, little attention has been paid to the service level agreements (SLAs) that most service providers have to adhere to, as part of the service contract. In this paper we consider the problem of finding the minimum staffing requirement by modeling the support environment as an M/M/s queue while including an SLA type requirement. For the same system, we show that a lower bound on the service rate exists and how it is to be calculated. We also validate certain rules of thumb that software project managers can employ in light of changing conditions and discuss the caveats to these rules of thumb.