The cost of clinical laboratory testing has increased considerably during the past decade. This has prompted research and initiatives aimed at controlling clinical laboratory utilization without affecting the continued improvement of the quality of patient care. One of the most effective and proven approaches to clinical laboratory utilization management is the use of clinical test-ordering protocols. The major challenges being faced are those of modelling and specifying clinical guidelines and protocols in a manner that facilitates their integration into information systems, their subsequent management and their linking with electronic healthcare records. It is the authors’ belief that the event-condition-action (ECA) rule paradigm and modern database technology are of great potential in this area, and their applications here should be vigorously researched. This paper describes a generic model and language, called PLAN, based on the ECA rule paradigm for supporting clinical test-ordering protocols. The paper also discusses a database-based approach to the specification, execution and management of test ordering protocols.