Recent developments like the Advanced Distributed Learning (ADL) initiative emphasize the application of learning objects. Such modularization of learning content has large implications on the Instructional Design (ID) process. It requires innovation on a didactical, technical and organizational level. In this paper the actual implications of modularization of learning content in practice is discussed. We describe the results of a case study which illustrates the innovation of F16 maintenance training. In this case study we use a systematic and iterative approach to specify the ID requirements and to define prototypical lesson scenarios (Specifying Learning means in an Iterative Manner, SLIM). An important aim of the innovation was to increase training effectiveness and transfer of learning. The specification of task oriented learning objects is therefore very important. A challenge in this project was to create a coherent learning environment, despite of the fragmentation by means of learning objects. The most important steps in this study are: a) analyze the complex task, b) relate the critical desired behavior, conditions, and criteria for (minimal) performance of this task, c) select a relevant didactical model [we used the Four Components Instructional Design (4C/ID) model of van Merriënboer], and c) define the learning objects. All steps are conducted in intensive iteration and cooperation with the domain- and instruction experts. The chosen 4C/ID approach leads to defining a blended learning solution according to standardization developments of learning content to ensure reusability as well as the desired quality of education. This learning solution consists of the following components: paper based textbook, computer-based exercises, classroom-based teaching supported by multimedia, and emulation-based practice.