The good news is that organizations recognizing the need for both DA and IE do not have to do double work to adopt both disciplines. Because some of their objectives and methods overlap, and others are complementary, this interdisciplinary marriage can be accomplished relatively easily. The marriage will work on an organizational and management level because both disciplines examine similar information, pose many similar questions, and employ similar methods and processes. They both recommend the development of similar organizational frameworks and infrastructures, require similar planning, training and expertise, and require similar committed participation of many of the same stakeholders.
The marriage will also work on a technical level because both DA and IE modeling and architecture development activities employ similar structures and processes to partitioning information, albeit with different emphases. Both DA and IE systematically examine and partition information about the full life-cycles of multiple systems (or functions), decomposing and classifying, identifying commonality and necessary variability, and eliminating unnecessary redundancy.
Although other techniques are also usable, specialization analysis and decomposition analysis are two orthogonal techniques that, when combined, effectively support both the IE and DA partitioning process.
DA is primarily concerned with extending or tailoring reusable assets to form variants of similar systems. Therefore, the primary metaphor and partitioning mechanism of DA models is the generalization/specialization hierarchy. Nevertheless, decomposition is used, by some DA approaches, to model the context of operation for systems within a domain. It is also used to identify similar sub-structures within the domain (for feature comparison and component-based reuse), and to model the topology of the structural and dynamic relationships among them.
IE is primary concerned with combining reusable asset components to form interoperating systems. Therefore, the primary metaphor and partitioning mechanism of IE models is the decomposition/ aggregation hierarchy. Nevertheless, IE may occasionally employ specialization analysis to identify and partition functional and structural variants as required by stakeholders representing different user (i.e. functional) organizations and life-cycle stages.
IE and DA techniques are best combined by combining their scopes and primary partitioning mechanisms, starting with their respective planning stages. In this stage, a large problem space can be defined, consisting of multiple interoperating system families. This space can be partitioned into a high-level architecture of interrelated components. Each component known to have variants may be partitioned, in turn, into high-level specializations. Single components (or groups of several interrelated components) can be identified and prioritized as candidates for more detailed follow-on project stages. In these follow-on project stages, each partition (whether component or specialization) can be re-partitioned as required into lower-level components and specializations. IE techniques can be used to model the components, and DA techniques can be used to model the specializations. The high-level architecture can be used to coordinate the work of these projects, and to integrate their results into a growing asset base from which interoperating system variants will be composed.