Quality Requirements: Trade-off Analysis of Benefit and Cost

Would slightly better performance be significantly more valuable from a market perspective? Would significantly better performance be just slightly more expensive to implement? When dealing with quality requirements, we often end up in a difficult trade-off analysis. Aspects such as release targets, end-user experience, and business opportunities must be taken into consideration. But when is the quality level good enough? Berntsson Svensson et al. [1], pointed out that a major challenge by practitioners in industry is deciding when a certain quality level is good enough. Should the performance be two seconds, 1.5 seconds or even one second? To support release planning and roadmapping of quality requirements, we have developed the quality performance (QUPER) model [2, 4, 5]. The development of QUPER was carried out at two case companies in the mobile handset domain with a supplier-integrator relationship [5]. To apply QUPER in practice, the generic guidelines in Regnell et al. [4] were developed in cooperation between industry and academia. Moreover, the tailoring and evaluation of QUPER [2] were carried out by the researchers together with practitioners at the case company using an action research [6] approach.