System performance requirements: A standards-based model for early identification, allocation to software functions and size measurement

Background: In practice, the developers focus is on early identification of the functional requirements (FR) allocated to software, while the system non-functional requirements (NFRs) are left to be specified and detailed much later in the development lifecycle. Aim: A standards-based model of system performance NFRs for early identification and measurement of FR-related performance of software functions. Method: 1) Analysis of performance NFR in IEEE and ECSS standards and the modeling of the identified system/software performance functions using Softgoal Interdependency Graphs. 2) Application of the COSMIC-FSM method (e.g., ISO 19761) to measure the functional size of the performance requirements allocated to software functions. 3) Use of the COSMIC-SOA guideline to tailor this framework to service-oriented architecture (SOA) for performance requirements specification and measurement. 4) Illustration of the applicability of the proposed approach for specification and measurement of system performance NFR allocated to the software for an automated teller machine (ATM) in an SOA context. Result: A standards-based framework for identifying, specifying and measuring NFR system performance of software functions. Conclusion: Such a standards-based system performance reference framework at the function and service levels can be used early in the lifecycle by software developers to identify, specify and measure performance NFR.