ABSTRACT
A process standard is essentially a hierarchical task analysis (HTA) of a specified scope of activity. ISO TR 15504 has defined the format for such standards. Each process has a purpose, an outcome (a result, not an output), work products (inputs and outputs) and a description. The system engineering standard ISO/IEC 15288 and the HS model have three levels: process category, process, and practice. ISO TR 18529 has two levels: processes and practices. The performance of a process is assessed using a capability level, ranging from 0 (no achievement of results) through to 5 (optimisation to meet business needs) via l(ad hoc), 2 (monitoring of time and quality) and so on. Most software is developed by processes at level 1 (using appropriate models), and it is expected that most Human-centred design (HCD) assessments will be at levels 0 and 1.
