Last week I blogged about how performance problems manifest themselves: frustration, loss of revenue and disruption of development; and how adding hardware is a questionable solution. This week I'll blog about the first step to assure web performance.

It can be a valid choice to run the risk of performance problems in production and deal with them in a re-active manner. However, it is usually wiser to be pro-active and prevent them. This approach brings more certainty, peace of mind and also saves money. It consists of seven steps. Step 1: Define performance requirements.

Defining the performance requirements well usually is of under-estimated importance. Most of the time the requirement is formulated as: it just has to be fast or: at least as fast as the previous platform. With such vague definitions the confusion starts. The goal is unclear and is typically explained very differently by the business and the IT department. To prevent this, the goals should be formulated in a SMART way and be prioritized. Speed will be more important for a shop homepage than for a page where a customer can change his profile. By defining priorities, this order of importance is made explicit and clear. From SMART, the A stands for Attainable and the R for Realistic. These aspects are often ignored by the non-technical contributors to these requirements. In that case, a short response time will lead to an extended development time or expensive hardware. Half a second slower during peak hours can be acceptable if this saves tons of money. On the other hand, reducing the response time of an important page from 4 to 2 seconds can lead to a substantial growth in revenue. So, a solid analysis of the impact of performance on the business is needed to be able to clearly define the performance requirements in a SMART way, prioritized and be able to balance the cost and benefits.

Next time we’ll deal with step 2: Execute a performance PoC.

Tags: Java, Performance, requirements
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