Performance problem

Performance tuning is the activity of improving the performance of a system. This is typically a computer application, but the same methods can be applied to economic markets, bureaucracies or other complex systems. The motivation for such activity is called a performance problem, which can be real or anticipated. Most systems will respond to increased load with some degree of decreasing performance. A system's ability to accept higher load is called scalability, and modifying a system to handle to higher load is synonymous to performance tuning.

Systematic tuning follows these steps:

Assess the problem and establish numeric values that categorize acceptable behaviour.
Measure the performance of the system before modification.
Identify the part of the system that is critical for improving the performance. This is called the bottleneck.
Modify that part of the system to remove the bottleneck.
Measure the performance of the system after modification.

This is an instance of the measure-evaluate-improve-learn cycle from quality assurance.