Ease of use doesn't come from wishful thinking. It comes from conducting systematic usability engineering activities throughout the project lifecycle. This is real work and costs real money, though not as much as some people fear.

You can conduct simple forms of user testing in a few days and gain extensive insights into both user behavior and recommended design improvements. Still, before most people will commit to a lifecycle approach to usability, they want to know what it will cost and what they will gain. We set out to find the answers.


To assess the total cost of usability (as opposed to the price of a single test), wecollected data from 863 design projectsthat included usability activities. Depending on how we estimated it, usability costs were between 8% and 13% of the projects' budget.

Based on this finding and findings from other surveys, we conclude that current best practices call fordevoting about 10% of a project's budget to usability.

我们的完整调查数据显示了一个略微复杂的数学模型,将项目规模与建议的可用性支出相关。从本质上讲,可用性的成本与项目规模没有线性增加,因为许多可用性活动成本大致相同,无论项目有多大程度如何。一个项目十倍更大例如,通常只需要four times more usability spending.

Usability Benefits


我们发现的42双措施平均,usability increased by 135%when we excluded five outliers with exceptionally big usability improvements. (If we include these outliers, the average improvement jumps to 202%.)

The improvement in usability metrics differed depending on the metric, as the following table shows:

Metric Average Improvement
Across Web Projects
销售/conversion rate 100%
Traffic / visitor count 150%
User performance / productivity 161%
Use of specific (target) features 202%

Our current study does not include intranet redesign projects. However, based on ourstudies of intranet design potiential, I estimate that the average improvement inIntranet可用性指标有点低于100%.

That intranet usability appears to increase slightly less than website usability is easily explained.网站可用性是由用户避免错误的能力主导在导航和解释新信息。例如,我们从网络前时代的计算机设计项目收集的数据显示,可用性可以显着提高错误避免熟练的用户性能。如果Web可用性与避免错误密切相关,Intranet可用性是避免避免和熟练的用户性能的混合:在管理良好的内联网中,用户只处理单个设计,因此最终实现了熟练的性能。

Estimating ROI

In terms of gross averages, I estimate thatspending about 10% of a project's budget on usability activities doubles usability. Unfortunately, such estimates do not produce an ROI number in the classic sense, because the two parameters are measured in different units: project cost is measured in money, and usability is measured in increased use, more efficient use, or higher user satisfaction.

Converting usability improvements to dollars is easy for e-commerce, where doubled sales have an immediate value. Forintranets, productivity gains转换为货币估计数也很容易:简单地将员工每小时成本节省的时间乘以。


通常,the more people use a design, the bigger the usability ROIsince the benefits come from the added value that ease of use brings to each user. Doubling sales on a large e-commerce site obviously results in bigger numbers than on a small one.

Similarly, theestimated productivity gains from redesigning an intranet为了提高可用性,比一家拥有1000名员工的公司的成本大8倍,这是一家拥有10,000名员工的公司更大的20倍,一家拥有100,000名员工的公司更大的50倍。

Because usability gains far exceed the costs, I believe thatthe budget share allocated to usability will increase in the future, at least in big companies. Currently, I recommend spending 10% of a project's budget on usability, butwithin a few years最佳ROI可能需要花费20%或更多。显然,有一个点,额外支出的可用性的价值将小于其他项目组件的额外支出的价值。但是,我不知道那里的回报点递减,因为我们在目前的实践附近。