There are situations when a programme may not have achieved its intended goals. In such situations, there are two possible causes: the content of the intervention and the way it is being delivered. It is to make sure that an intervention is being delivered effectively that you undertake process evaluation. It involves identifying problems with the way a service is being delivered to consumers or finding ways of improving the delivery system. Evaluating the delivery manner of a programme is a very important aspect of process evaluation. There are a number of issues in delivering a service that may impact upon its delivery manner and process evaluation considers them. Some of the issues are: