Performance engineering

As the connection between application success and business success continues to gain recognition, particularly in the mobile space, application performance engineering has taken on a preventative and perfective role within the software development life cycle. As such, the term is typically used to describe the processes, people and technologies required to effectively test non-functional requirements, ensure adherence to service levels and optimize application performance prior to deployment. The term performance engineering encompasses more than just the software and supporting infrastructure, and as such the term performance engineering is preferable from a macro view. Adherence to the non-functional requirements is also validated post-deployment by monitoring the production systems. This is part of IT service management (see also ITIL). Performance engineering has become a separate discipline at a number of large corporations, with tasking separate but parallel to systems engineering. It is pervasive, involving people from multiple organizational units; but predominantly within the information technology organization. Because this discipline is applied within multiple methodologies, the following activities will occur within differently specified phases. However, if the phases of the rational unified process (RUP) are used as a framework, then the activities will occur as follows: During the first, Conceptual phase of a program or project, critical business processes are identified. Typically they are classified as critical based upon revenue value, cost savings, or other assigned business value. This classification is done by the business unit, not the IT organization. High level risks that may impact system performance are identified and described at this time. An example might be known performance risks for a particular vendor system. Finally, performance activities, roles and deliverables are identified for the Elaboration phase. Activities and resource loading are incorporated into the Elaboration phase project plans. During this defining phase, the critical business processes are decomposed to critical use cases. Probe cases will be decomposed further, as needed, to single page (screen) transitions. These are the use cases that will be subjected to script driven performance testing.