The ADDIE model is a five-phase instructional design model that is commonly used by instructional designers to develop effective training programs. The five phases are analysis, design, development, implementation, and evaluation. In the analysis phase, learning needs are identified. In design, learning objectives are established. Development involves creating instructional materials. Implementation is delivering the training. Evaluation assesses the effectiveness of the training. The ADDIE model provides a systematic approach to creating instruction but can be time-consuming and require revisions between phases.