5.4 Making the Business Case

Software architecture has many potential benefits. Some adopters of the architectural practices do not realize these benefits. Many of these shortfalls are the result of the inadequate practice of architecture principles and disciplines. Some key benefits of software architecture include various forms of reuse, which can provide benefits such as reduced risk, reduced cost, and reduced time to market. Another important benefit of an architectural approach is interoperability. Interoperability can be realized only if the computational architecture is managed appropriately for application system development across an enterprise. We covered some significant success stories for object orientation and object technology in Chapter 3. In addition, many other documented studies show how the technology can provide benefits if it is applied properly.

One of the best collections of object technology success stories is Paul Harmon and William Morrissey's book, The Object Technology Casebook [Harmon 1996]. It documents 18 case studies of projects that were award winners in an annual competition sponsored by Computer World. Some examples include a Smalltalk application by Allied Corporation where they realized a 2400-to-1 reduction in operational cycle time. In other words, the cycle time for performing their task was reduced from 9 weeks down to 9 minutes through the use of an object-oriented information system. In addition, this application reduced the required personnel from seven down to one, and the qualifications of that person were reduced to a novice level, whereas formally they needed experts. In addition, because of the reduction in staff there was a corresponding reduction in the amount of capital required to perform this application capability.

Other examples from the casebook include several systems at Boeing, one of which reduced the time to market by 30% and reduced the time on some tasks by up to a factor of 10. In another Boeing case study, they reduced the production costs up to 20% on their applications. The general results for reuse benefits are fairly consistent, in that the primary benefit is through the reduction in system development time, which can be as large as 70%. The actual cost savings, including the development of the reusable software, usually hovers around the 10 to 15% level because the development of reusable software does require extra effort.

Another consideration is that most of the documented success stories for software reuse are based upon companies developing software for commercial applications and applying that software to multiple commercial applications, instead of applying the software to internal applications.

Simplify designs by minimizing the number of interface operations.

In Figure 5.4 we describe the primary paradigm shift at the architectural level for how new systems can be constructed using object technologies to provide enhanced benefits in system extensibility and reduced complexity. Figure 5.3 is an example of this paradigm, showing how many of the available standards only provide interoperability among vertical functions of the same kind. It is in the interoperability across vertical functions in a horizontal sense that the true benefits occur.

In Figure 5.4, a revised architectural concept adds the horizontal capability to the vertical integration. Figure 5.5 shows the potential benefits of a hypothetical environment using the various kinds of architectural approaches. If the traditional approach called custom integration is applied, the types of systems that are constructed resemble the stovepipe configuration and quickly escalate in complexity, such that the benefits of interoperability are overcome by the cost of creating and maintaining the integration solution.

With highly coordinated integration, it is possible to reduce the complexity and cost of extension down to almost constant factors. However, this level of coordination is not possible or practical in most organizations today. With vertical types of standardization, the benefits do not vary significantly from custom integration, so there is a category of vertical architectural standards that does not provide significant leverage across a wide variety of applications. In the fourth column in Figure 5.5, the hybrid architecture approach allows a variation in the level of benefits that can be controlled by the application architect. Further details of how this approach is implemented are given in The Essential CORBA [Mowbray 1995].

Figure 5.6 translates these concepts into dollar figures for a hypothetical enterprise-wide system integration project. To achieve interoperability across this organization with 20,000 users and 50 applications, the potential cost is as high as a billion dollars, or $50,000 per seat. The numbers are based upon experiences and lessons accrued over the last 10 years. The cost could be as high as $40 million if the system were to be extended by tying one new application into the existing 50. If two companies that have already performed custom integration across the board were to be merged, which is not an unusual occurrence, the cost of integrating them could be as high as $2 billion. If a proper architectural approach to systems integration is applied, the cost could be substantially reduced. If a common architectural solution that applied across all 50 applications were applied, the cost of integration could be reduced to $500 per seat. The addition of a new application could be reduced as low as $10 per seat, and if the two organizations supported the same coordinated specifications, it might already be the case that their internal systems would interoperate without modification.

Architect a small horizontal interface supported by all components.

This section discussed several aspects of the business case for object technology. Paul Harmon and William Morrissey's The Object Technology Casebook [Harmon 1996] includes many examples of how object technology has helped organizations reduce costs in time to market. The key to applying object technology effectively is the proper application of architectural principles and practices. Through these principles, it is possible to achieve some dramatic kinds of results in integrating systems across large-scale enterprises. These results scale down to small application configurations as well.