Answer: Level 1 – Constraint Requirements
This level involves staffing, budget, and schedule. The business requirements are frequently defined as a set of objectives described on several pages of narrative description. Thus, it becomes the role of the project team to expand the initial definition and build the software. However, management and the end user of the software will manage more by the constraint requirements than by the business requirements. The result is that the software put into production on the scheduled date may miss many key requirements, which will need to be installed after the operational date but under new budgets and schedules.
Level 2 – Business Requirements
This level places its emphasis on the functional and operating requirements. Level 2 establishes the criteria that the deliverables must meet in order to be accepted by the end user. At this level, standards are established for the requirements document which specifies the totality of requirement attributes that must be included for the requirements to be considered complete. These often include defining how the requirements will be tested, the objective of therequirement, the problem that the requirement is designed to solve, a detailed description of the requirement, and how the requirement is related to the objectives to be accomplished. Many information organizations at this level introduce uniquely identifying requirements, and then utilize processes that trace requirements through the entire software-building process.
Level 3 – Relational Requirements
This level emphasizes relationships within an information system and between information systems. Level 2 defines relationships, but normally at a much lower level than Level 3. Level 2 relationship specifications tend to be within an individual application system. Level 3 relationships focus on organizational databases, processing sequences and priorities, intersystem relationships, and processing cycle relationships. Data relationships help eliminate data redundancy and help assure consistency of use of data throughout an organization. Processing relationships address processing priorities and processing sequences. The system relationships deal with interfaces between systems and changes to systems. The larger challenge is assuring that all systems are changed concurrently when they are impacted by a common change(s). The processing cycle or timing relationship assures that all data that belongs in a particular accounting processing cycle is processed during that cycle.
Level 4 – Quality Requirements
Quality requirements are the characteristics surrounding the functional requirements that facilitate end user satisfaction. An example of quality requirements is ease of use. The functional requirements deal with the data specified for a particular product, but if it is very difficult to use (i.e., not meeting the quality ease of use requirement); the end user tends to be dissatisfied.
Level 5 – Reliability Requirements
Reliability primarily deals with mean time between failures. To achieve reliability requirements necessitates building a database of processing information and performing adequate statistical analysis on that data. Then a statistical prediction of reliability can be made. While the end user needs to specify reliability requirements, they can only be measured and achieved through the use of statistical tools. Figure 44 shows the best practices for deliveries process.
