Friday, 23 October 2009

Usability Assurance

A post to introduce usability assurance. The aim of ergonomics in this context is to provide assurance that a system or product will be operable by those who are intended to use and maintain it.

The approach was first proposed by the US General Accounting Office (1981) "What assurances are there that weapon systems developed can be operated and maintained by the people who must use them?" supported by an assessment toolkit.

Basic premise

An organisation with clear HCD processes is likely to produce usable products. An organisation where HCD is unclear is likely to produce unusable products.

If we wait until after the system is designed to find out how easy it is to use, it is usually too expensive to make improvements.

What is it that leads to ease of use? The answer is Human Centred Design (HCD). An organisation that has well-defined processes for HCD can be fairly sure of producing a usable system. An organisation with ad hoc processes is likely to produce a system that is hard to use.

[Note: ‘process’ means a continuing area of concern, or a collection of related responsibilities. It does not mean ‘method’ or ‘series of steps’].

A health check (process assessment), followed by business-driven process improvement will reduce the risk of an unusable system being developed.

What is new(ish)

Having the means of assessing the capability of an organisation to deliver a usable system. This provides a lead indicator to use as a management tool, in addition to the more traditional assessments of product characteristics and its resulting performance in achieving user goals.

Although process models in the form of HCD Standards have been published since about 2000, their use as process models has been limited, and they have mostly been used for guidance. The opportunities for assessing capability are considerable, and would be extremely cost-effective e.g. to support purchasing or licensing decisions.

The ergonomist’s point of view

A metaphor for life: There is always room at the bottom

Many ergonomists are committed to an entirely technical career and have no aspirations to management. Usability assurance is not really for them. The consequence of staying technical is of course that you will be ignored, overruled and brought in when it is too late to do anything useful, but not too late to demonstrate that ergonomics can fail.

For those ergonomists who would like to be in a position to influence corporate or project management, usability assurance is the way to go (up).

The customer’s point of view

Quality In Use is defined as: The degree to which a product used by specific users meets their needs to achieve specific goals with effectiveness, efficiency, safety and satisfaction in specific contexts of use.

Achieving Quality In Use sounds like ‘reason for purchase’. For the customer, it is vital to find the correct supplier(s). Once the wrong team is under contract, there is very little that can be done. An assessment of capability before the contract is placed eliminates a huge amount of risk. A self-assessment eliminates some more. Mandated process improvement in the contract (yes, it has been done) can mitigate the remainder. Demanding HF deliverables, or HF specialist involvement does little on its own to mitigate any risk.

The project manager’s point of view

ISO 13407 is the key standard for HCD and was written with the project manager in mind. The HCD process models support this and give the project manager the tools to know where the risks are ahead of time. This is a big change. Up to this point, ergonomists have represented a cost and a risk – albeit with some potential benefits for the end user and the customer organisation. This is why ergonomics is so hard to sell. Usability assurance is the first development that makes ergonomics attractive from a project management point of view.

The engineer’s point of view

For many softare engineers, saying “we have CMM for Human Factors” produces instant and complete understanding. Software engineering has had capability evaluations for about fiteen years. More generally, the process models focus on the needs of the project, rather than the needs of the ergonomist, and consequently make integration easier. The HCD principle of multi-disciplinary teamwork helps too. The flexibility provided by a process approach, (compared to say a Human Factors Integration Plan without a process overview) becomes important in a rapid development context.

The user’s point of view (last as usual)

Of course, one of the principles of HCD is “the active involvement of users and a clear understanding of user and task requirements”, so some users are going to be involved. For them, the usability assurance approach gives them an overview of how things are going, which enables them to judge their input appropriately. For the other users (not directly involved),

For users involved in the design process e.g. as participants in usability trials, the assurance approach gives them an idea of the risks associated with what is coming down the line.

Note on alphabet soup

The standards numbers quoted are all changing and becoming part of ISO 9241, but that is still in progress, and some readers may be familiar with the numbers used here.

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