The ability to measure the extent to which good practice is being followed (using ISO TR 18529) is likely to promote user-centred design, on the principle of "what gets measured gets done”. It also raises the competitive stakes by enabling suppliers to provide validated product endorsement based on process metrics.


Process models offer the potential to change the custom software business model.  Usability engineers can form an alliance with the customer.  There is a sector of the software supply industry that depends on poor usability for economic survival.  The strategy is to bid at below cost for fixed-price competitively-tendered supply against a contracted set of requirements.  They then deliver a system; it meets the requirements (so they get paid) but it is unusable, leading to large quantities of profitable post-design support.  The inclusion of ISO 13407 in the contract, with the use of ISO TR 18529 for assessment purposes, frustrates this strategy in a way that methodologies, guidelines, handbooks, or expert consultants cannot. 

Software Engineering has made the move from methodology to process with the development of standards such as ISO 15504, the Software Engineering Institute's Capability Maturity Model (CMM), ISO 12207 and ISO 15288. The development of a process model for user-centred design that is compatible with engineering models and quality standards (e.g. ISO 9000:2000) enables usability professionals to form new alliances (with quality managers, process architects and Software Process Improvement initiatives), and to take advantage of accepted initiatives for process improvement.

An alliance can be made between usability engineering and business-level metrics.  For example, in Europe the European Foundation for Quality Management (EFQM) business excellence model is becoming widely adopted for organisational benchmarking (equivalent models are used in the US and Japan).  The approach and content of the EFQM are compatible with ISO TR 18529, offering the opportunity for usability process metrics to be included at corporate level.

HSI  should provide a service to a broad range of project stakeholders.  The format of the HS model and the UMM speaks the  language of key stakeholders, including project sponsors.  The designed-in integration with system engineering offers the prospect of multi-disciplinary design and team working in  a way that is currently the exception rather than the  rule.

Perhaps  the key value of process models is as lead indicators, as has been shown  repeatedly for software CMM.  In a negative sense, if the project does not have human-centred processes in place,  then the only way it can possibly deliver an operable system is by massive  amounts of heroism.  In a positive sense, if the project has the right processes in place to mitigate identified risks, then it can proceed with confidence.  Performance indicators from simulations or prototypes only achieve good predictive capability after resources have been committed and many key decisions made. 

The UMM sets out the scope of activity required for Human Centred Design of a product such as an IT system.

The  HS model sets out the full scope of HSI activity, covering both system  acquisition activities and activities required for Manpower, Personnel and Training.  As such, it provides a shared  framework for the project stakeholders to understand their responsibilities, and  to identify strengths and opportunities for improvement.  Process-based workshops at project start-up  can start to instil human-centred attitudes and approaches.  Members of the Integrated Project Team can  start to adopt ownership of appropriate processes and build it into their planning.

The  HS model and UMM provide the ability to conduct Capability Evaluation on potential  suppliers. 

For suppliers of usability services (as opposed to products or systems) the UMM has formed the basis for a scheme to assess the organisational competence. This is discussed further at the Competence page.

Capability Evaluation is particularly useful to HSI because it can focus on outcomes produced by the  project rather than, say, deliverables produced by specialists.  Whilst this particular benefit has driven the form of the HS model and its compatibility with other process standards, it is not expected that this will be common during the early use of the model.  Further, it is expected that assessments will be at the level 0 - 1 end of the capability scale for some time to come.  It is considered that setting the equivalent of software CMM® Level 3 would make an excellent 'stretch target' but would be difficult to  implement immediately.

On many current projects, it is inevitable that many suppliers will not have  implemented a human-centred approach.  Where this occurs, the HS model provides the resources to improve the situation in a number of ways.  Firstly, a quick assessment of such a supplier will identify the risk and get it tracked, hopefully with assignment of resources to help the customer to manage the risk.  Next, a Process Improvement programme can be agreed with the supplier (preferably as part of organised supply chain management), and progress can be monitored and reported.  Early experience on a project with one supplier can provide encouragement to any subsequent occurrences that the issue can be resolved without untoward cost and programme impact. 


Critical Success Factor

As opposed to...

How Usability Assurance delivers this

Support international, commercial procurement

MOD/DoD specific methods

ISO approach

Integration with system engineering

Standalone HF Isolation

Compatibility with software and system engineering standards and approaches

Support to Smart Procurement, partnering

Detailed specification, no risk transfer

Co-operative Process Improvement, Assessment of all stakeholders

Risk-driven approach, compatible with rest of project risk management

Prescription, or specialist approaches

process assessment and improvement as risk mitigation

Coverage of Manpower, Personnel, Training as well as equipment acquisition

HFE only

HSL model covers PPO, Customer 2, Customer 1

Link to project/programme evaluation, demonstration of Value For Money


Supports the development of business-level Performance Indicators


How HFI or HSI fails

How Usability Assurance prevents this

Presentation as specialist, obscure set of knowledge

Presentation as system engineering discipline

Emphasis on testing (cf. Commercial usability labs)

Whole project scope, with emphasis on strategy

400 page text books as guides, info for non-specialist


HF push, jobs for the boys with no obvious benefit to the project manager

Outcome-driven, role-independence

Demand for time-consuming methods with unclear benefits

Assurance of delivering outcomes

Work activities with no obvious useful outputs

Work products that are compatible with software and system engineering



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