Requirements are detailed descriptions of the system, in terms of use cases, specifications and other non-functional constraints. They are critical in guiding the detail designs and verifying the final system. However, they are not sufficient or effective in defining and communicating the big picture, especially for large, complex software systems. For the whole system, people need to know the long term values, the fundamental principles, the main technologies and the overall strategies. That is what we call the vision of the software system, or at system level, what to achieve and how to achieve them.
Software vision serves several purposes. First, it serves as the bridge between the business world and engineering world. As we know, business and engineering use different languages and have different focuses. Software vision translates the judgment of business values to the guideline of engineering activities. From the business point of view, software vision states the overall value level that a software system can ever reach. From the engineering point of view, software vision is the ultimate goal of the architectures and designs. The articulation of software vision is the joint effort of business analysis and technical analysis, but serves as the demarcation of business and engineering activities. Second, software vision builds a long term value proposition and strategy so that software development can be conducted in a relatively stable context. It is a buffer between the ever-changing requirements (the faster moving business world) and the long-lasting development (the effort-taking engineering world), which is very helpful to architecture definition and system level designs. Because software vision is the abstraction of the system requirements and derived from deep understanding of the company business and market trend, the software system built on right vision can satisfy not only the current requirements, but also the long term business growth. Through the right vision, you can be sure that the system accomplished half year, one year or years from now can still deliver the expected technical advantages and business values. That is why we say "software is built on vision not on requirements". Third, software vision dictates the basic strategies and approaches about how to build the system. Many times people spend lots of resources and efforts on meeting the fierce deadlines and delivering the detailed requirements, only to find out, very late into the development, that the basic assumptions and approaches they have taken are flawed. With the right vision, a software system can be built simpler, faster and cheaper. Otherwise, no matter how good the design and how strong the team, the development efforts are heading towards the wrong direction and will eventually fall apart.
Through the years, we have learned the critical role played by vision articulation and have set up a pragmatic process to come up with the right vision early in the software development. Our broad domain knowledge, strong analytical ability, innovative thinking, and vision-driven approach can guarantee that your development moves to the right direction and in the most efficient way.
