This Technical Specification presents a human-systems (HS) model for use in ISO/IEC 15504-conformant assessment of the maturity of an organization in performing the processes that make a system usable, healthy and safe. It describes processes that address human-system issues and the outcomes of these processes. It details the practices and work products associated with achieving the outcomes of each process. The model describes processes for specifying and evaluating usability, health and safety, but it does not address all processes relating to their achievement. The model will always be tailored to the specific organizational and system context prior to use in assessment. Annex D provides advice on tailoring process models for a range of uses. The HS model does not define the roles or competencies of staff who perform HS processes. This Technical Specification is intended for use by process assessors and those developing process assessment models and tools. It may be informative for those responsible for human factors activities and human factors specialists. The latter groups of readers should familiarise themselves with the vocabulary of process modelling and process assessment prior to reading this Technical Specification. The Bibliography lists informative standards and texts. This Technical Specification is intended to be used in conjunction with ISO 13407 and ISO/IEC 15504. The latter standard provides the framework in which the process descriptions in this Technical Specification may be used. This Technical Specification defines an additional category of processes for use with other process standards, for example ISO/IEC 12207 and ISO/IEC 15288. NOTE 1 Readers of this Technical Specification are expected to be familiar with ISO 13407 and ISO/IEC 15504.