The Computer Architecture, as discussed above, relates to the Information Architecture, the Data Architecture and the Systems Architecture. This level is primarily made up of the specific hardware and software that constitutes the technological base for the above architectures. The choice of specific hardware and software requirements is also determined by the products available in the market and the budget allocations. Specific 'make or buy' decisions are generally made at this level, however they are guided by the issues at other levels. For instance the decision to outsource the firm’s Telecommunication setup or Data Center centers, although a technology decision, is guided by issues such as development of proprietary knowhow, and focus on the core competencies.

The above discussion has provided a simplistic view of the various architectures that form the basis for the firm’s Information Systems Development Initiative. However, it must be observed that several elements discussed under various levels have cross-level implications. For instance, the decision related to Client-Server is not just a technological decision, it has implications for the firm’s productivity, human resources, and competitive advantage . Similarly, decision about Intranets entails financial, technological, and business aspects.

A going firm, however, needs to observe a caveat: these decisions are more complex when the firm has to make future decisions when adding on to these architectures. However, if a firm considers the interrelatedness of the various architectures in the early stages of IS Planning, such decision-making should prove to be a more organized and manageable activity.