AMOS, JULY, 2002
Solve basic problems in demand engineering
introduction
Today, economic and social life has a sharp growth in software, and software demand is increasingly complex. Software development has become a comprehensive team event with scope of skill, responsibility and time. Practice has proved that a good demand project is critical to reducing development costs and the success of the project. According to the statistics of the authority, in the world, only one quarter of software development projects can meet customers' goals within the prescribed time and budget. Throughout these projects successful projects, the excellent demand project is a common part of successful experience.
Demand is the goals and abilities that must be achieved by systems or software; the success of the development team is to meet the needs of software projects. Software demand engineering issues have a comprehensive connotation: including problem-based demand capture, establish simple prototypes, establish analysis models, development requirements, corresponding audits, and comprehensive management.
The domestic software industry starts late, the starting point is high, the task is urgent, and there are many problems in software demand engineering. In the thousands of Wanxu, the primary focus should be implemented in the foundation, and there are two aspects of the problem: the Elicitation and the Spectation. Solving the basic problem can not only make short-term effects, but also lay a solid foundation for the overall level of demand.
Chart 1 Software Demand Engineering Overview
Capture method
Capture needs are to guide customers to say what they want and confirm that the content recorded is indeed what they want. If the capture method of the demand is not properly or improper, it is usually exposed.
First, software demand cannot reflect the truly need of the user. A more common misunderstanding is the simple and complex extent of demand. Deterns whether the user can really understand the content: mistakenly think that customers can only understand simple needs, but there is no direct help to development; only complex needs is useful, but Most users can't understand. In fact, the main reason for this type is that the demand for capture cannot reflect the user's perspective, and it is difficult to judge whether the demand is complete and correct, especially in the development activities.
Second, software requirements cannot be directly shared by different types of types of work. In theory, the work content of all members of the development team is subject to software demand; in reality, if the ideal demand capture method is not used, only the analyst's work looks directly and the content of the software needs, other people's work content and software The association of demand is not intuitive, and the differences in forms or transcripts are often not easy to detect many dismissions, redundancy or deletions.
Use Case as a capture method of software requirements, in the case of utilization, can solve the above two problems well.
First, USE Case is a carrier of software requirements, and is also a communication method for discussing software requirements. The maximum feature of the USE Case method is to fully reflect the perspective of the software user. The requirements organized by the USE CASE method have both a glimpse of the graphics, and in-depth meticulous text descriptions, from macro to micro, regardless of factor, it can reflect the user's perspective, and thus can be fully understood by the user. In other words, the user may judge whether the captured software needs can meet their true needs, so that the two sides have reached a consensus early. See the figure below.
Chart 2 USE Case Graphical Description
Second, the software demand based on the USE Case organization has a significant export-oriented characteristic, which is a highly reused labor outcome. Use case support analysts help users understand what system can do, help designers identify basic elements in moderate issues, help project managers to predict the workload of development tasks, and provide direct use for test activities and user document editing. Basis and blueprints. See the figure below.
Figure 3 USE CASE content is directly shared by multiple types
The specific organizational form of content organization demand is primarily targeted for Software Demand (SRS), there are two prominent issues.
First, it does not meet international standards. The main symptoms are unclear, often the simple stack of the details of the demand details of the intensive software, and it is difficult to understand the software products from the high-level "why?".
Second, the process guidance related to software demand is weak. On the one hand, obtaining high quality software demand is over-dependent on the experience of analyst itself, limiting the feasibility of parallel development demand; in addition, facing valuable software demand content, team members cannot fully utilize.
The Rational Unified Process As the industry's factual standard for software development processes, its mature document system and its corresponding process counseling, in the case of utilization, can solve the above two problems well.
First, the software demand in Rational Unified Process is consistent with the International Specification IEEE830-1998, and the content is divided into an overall number of descriptions, detailed description and support information, etc., each part of the content is clear, and the association is clear. The functional requirements described in USE CASE are smoothly integrated in software requirements. At the same time, Rational Unified Precess provides detailed guidelines and checkpoints for the preparation of software requirements to ensure the quality of collaborative jobs. See the figure below.
Chart 4 and the relevant guidance related to software requirements
Second, revalting the demand for software, Rational Unified Process provides a wealth of process guidance. The basic content of the software demand is based on the "Request" request, ensuring the demand content reflects the user's requirements; the guiding principle of software demand is based on "foreground", ensuring specific content and high-level positioning anastomosis; software demand Description Strictly abide by the "vocabulary", shields ambiguity from the microscopic level. In the Rational Unified Process, the content of software demand is contracted as a software development plan, software frame document, analysis model, design model, and test model. The process not only describes the association between these critical workpieces, but also for content mapping and The conversion gives specific suggestions and verification points. See the figure below.
Chart 5 Ripe document system for Rational Unified Process
to sum up
The capture method and content organization of the demand are the basic issues in the demand project. The corresponding work contents directly reflects the core value of the demand, and has established a good start for the development and completion of the demand engineering. In the basic problem, it is not possible to solve the so-called "management" before it is only possible to make some surface articles, and even the opposite.
Of course, it is unique to solve the problem. The scheme introduced in this article is a deep heritage, which is based on the best experience accumulated by the Rational Software's focus on software engineering. It is the mainstream direction of the industry.
