Cost-benefits were calculated using the recommended
The maturity briefings and assessments cost
£9800 in IR/EDS staff time.
The methods used to improve JADs were:
context of use analysis, set usability requirements,
task analysis, task scenarios, preparation pack, paper prototyping,
managing issues, using smaller teams, a project glossary, affinity
diagramming and style guides.
These brought a degree of engineering to the
workshops that hadnt previously existed, and provided a framework
for end users to make an effective contribution.
For a system with 20 functions the value of
the total saving in staff time is estimated to be £231,000 (385,000
Euro). The cost of using these methods in JADs is estimated to be
£88,500 (147,500 Euro), giving a cost benefit ration of 1:2.6
for these methods.
Evaluation of the existing system, several prototypes
and live running cost a total of £51,500. Evaluating an existing
system clarified requirements, and the evaluations ensured that
the requirements were met and enabled additional improvements to
be made, which will lead to benefits in use.
It has not yet been possible to estimate the
use benefits, but usability testing verified that staff could complete
and to acceptable quality standards on their first day of using
the on-line system. The user centred methods employed during development
that ensured that the system was designed to meet real work scenarios
played an important part in achieving these results.
Overall cost benefits
The overall cost of the maturity assessments,
development and evaluation methods was £152,000 (253,000 Euro).
The cost benefits of using all these methods based only on estimated
savings in development costs, is 1:1.5. The potential benefits
of savings in use have not yet been estimated, but are likely to
be substantial, with 30,000 users whose time costs over one Euro
a minute. Thus the actual cost benefits of using these techniques
was almost certainly much higher.
The value of the methods to the business was
sufficiently clear at the time of the second maturity assessment
to commit to their wider usage without the need for a cost-benefit
analysis. This analysis confirms the value of that decision.
Other parts of the
Inland Revenue case study:
User Centred Design
Last updated 11-Oct-00.