Human centred design processes for interactive systems
ISO 13407 provides guidance on achieving quality in use by
incorporating user centred design activities throughout the
life cycle of interactive computer-based systems. It describes
user centred design as a multi-disciplinary activity, which
incorporates human factors and ergonomics knowledge and techniques
with the objective of enhancing effectiveness and productivity,
improving human working conditions, and counteracting the
possible adverse effects of use on human health, safety and
performance.
There are four user centred design activities that need to
start at the earliest stages of a project. These are to:
understand and specify the context of use
specify the user and organisational requirements
produce design solutions
evaluate designs against requirements.
The iterative nature of these activities is illustrated in
Figure 1. The process involves iterating until the objectives
are satisfied.
The sequence in which these are performed
and the level of effort and detail that is appropriate varies
depending on the design environment and the stage of the design
process.
Figure 1: The interdependence of user centred design activities
ISO TR 18529: Human-centred lifecycle process descriptions
The EC INUSE project developed a structured
and formalised definition of the human-centred processes
described in ISO 13407. An improved version has subsequently
been published as ISO TR 18529. It is intended to make the
contents of ISO 13407 accessible to software processes assessment
and improvement specialists and to those familiar with or
involved in process modeling. It can be used in the specification,
assessment and improvement of the human-centred processes
in system development and operation.
The Usability Maturity Model in ISO TR 18529 consists of
seven sets of base practices (Table 1). These base practices
describe what has to be done in order to represent and include
the users of a system during the lifecycle. The model uses
the format common to process assessment models. These models
describe the processes that ought to be performed by an organisation
to achieve defined technical goals. The processes in this
model are described in the format defined in ISO 15504 Software
process assessment. Although the primary use of a process
assessment model is for the measurement of how well an organisation
carries out the processes covered by the model, such models
can also be used as a description of what is required in order
to design and develop effective organisational and project
processes.
Human-centred design processes and their base practices
Ensure HCD content in system strategy
Represent stakeholders
Collect market intelligence
Define and plan system strategy
Collect market feedback
Analyse trends in users
Plan and manage the HCD process
Consult stakeholders
Identify and plan user involvement
Select human-centred methods and techniques
Ensure a human-centred approach within the team
Plan human-centred design activities
Manage human-centred activities
Champion human-centred approach
Provide support for human-centred design
Specify the stakeholder and organisational requirements
Clarify and document system goals
Analyse stakeholders
Assess risk to stakeholders
Define the use of the system
Generate the stakeholder and organisational requirements
Set quality in use objectives
Understand & specify the context of use
Identify and document user’s tasks
Identify and document significant user attributes
Identify and document organisational environment
Identify and document technical environment
Identify and document physical environment
Produce design solutions
Allocate functions
Produce composite task model
Explore system design
Use existing knowledge to develop design solutions
Specify system and use
Develop prototypes
Develop user training
Develop user support
Evaluate designs against requirements
Specify and validate context of evaluation
Evaluate early prototypes in order to define the requirements for the system
Evaluate prototypes in order to improve the design
Evaluate the system to check that the stakeholder and organisational requirements have been met
Evaluate the system in order to check that the required practice has been followed
Evaluate the system in use in order to ensure that it continues to meet organisational and user needs
Introduce and operate the system
Management of change
Determine impact on organisation and stakeholders
Customisation and local design
Deliver user training
Support users in planned activities
Ensure conformance to workplace ergonomic legislation