Abstract Designing specifications for technically advanced instructional products, such as e-learning, simulations or simulators requires different kinds of expertise. The SLIM method proposes to involve all stakeholders from the beginning in a series of workshops under the guidance of experienced instructional designers. These instructional designers ensure that specifications are designed in a systematic, iterative, way based on instructional design and development models. The workshop participants, however, bring in all the necessary information and they take all the decisions. The SLIM method is geared towards the first phase of the instructional design process: designing a needs statement in the form of a first set of global user requirements. It has been used in eight case studies. The results of these case studies have led to improvements to the method and suggestions for further research.