Usability activities typically account for 6% of development budgets whereas a more ideal budget was considered to be 10% (Nielsen, 1993). These small visible usability costs are far outweighed by the costs of deploying an application with poor usability and proposing to fix it later.

One study demonstrated that 80% of software costs occur after a product is released, in the maintenance phase. Of that work, 80% is due to unmet or unforseen user requirements, with only 20% due to bugs or reliability problems (Karat, 1993).

While the cost of IT development is measured, many business costs are often never directly attributed to poor application design because they are measured over time and in different parts of the business. These ‘hidden’ costs of any deployed system that has poor usability include:

• High error rates and low productivity
• Poor customer experience and loss of customers
• Decreased revenue
• Impact on staff morale and turnover
• Higher training and retraining costs as system changes occur
• Increased call centre traffic volumes and staffing.

Research indicates that it costs $1 to fix a problem in design, $10 to fix it during development and $100 to fix it post deployment (Boehm, 1981; Gilb, 1988).

And even with developments that do deliver a working system, a significant number of large software projects (63%) overrun their budget estimate (Lederer & Prasad, 1992). The four reasons rated highest by software managers were:

1. Frequent requests for changes by users

2. Overlooked tasks

3. User’s lack of understanding of their own requirements

4. Insufficient user-analyst communication and understanding.

Since a large proportion of the code in a system deals with the user interface (UI), it pays to get the UI analysis and design done effectively before coding starts.

These issues can be addressed by including usability as part of systems analysis and design rather than viewing usability simply as user testing and relegating it to the end of the development cycle.