The effectiveness of management and indicator processes is greatly enhanced when processes, products and outcomes are evaluated, and those evaluations are used to modify the cycles. Environmental conditions change, human values alter, policies evolve, and understanding of systems improves - all of which demand that all aspects of management systems be flexible, dynamic and adaptive.

Adapting management actions to optimise outcomes is the most important reason for evaluation, but should occur at all stages in the cycle and at several scales.

For example, the ability of a sampling program to deliver the intended detection of change must be periodically assessed. If the statistical power to detect change is found to be inadequate, then the sampling design needs to be modified, perhaps by increasing the frequency of sampling, the number of samples collected at each site, or the number of sites. Similarly, the cost-effectiveness of the indicator process has to be reviewed.

Adaptation occurs on different time scales. The diagram illustrates that evaluation of management actions might lead to their modification within weeks or months, but that evaluation might contribute to modifying planning activities, such as setting objectives, only over several years. Evaluation and adaptation should be included explicitly as part of the management cycle and indicator design.