Reduced Costs

Usability investments reduce development costs. The rule of thumb in many usability-aware organizations is that the cost-benefit ratio for usability is $1:$10-$100. Once a system is in development, correcting a problem costs 10 times as fixing that same problem in design. If the system has been released, it costs 100 times as much relative to fixing in design.


Integrating human factors input early in the product development lifecycle is very inexpensive, especially compared with the staggering costs of moving ahead without it. "Speeding up development is a key goal for integrating usability into product development. A one-quarter delay in bringing a product to market may result in the loss of 50% of that product's profit." (Bias & Mayhew, 1994). Maintenance efforts can be costly, particularly if a simple usability assessment or research initiative would have avoided the need for additional development. "One [well-known] study found that 80% of software lifecycle costs occur during the maintenance phase. Most maintenance costs are associated with 'unmet' or 'unforeseen' user requirements and other usability problems." (Pressman, 1992)