• Purpose of the Systems Development Life Cycle (SDLC) • The SDLC Phases
• SDLC Models
• Relationship between SDLC and Project Management
Purpose of the Systems Development Life Cycle (SDLC)
What Is SDLC?
The systems development life cycle (SDLC) is a structured methodology and process that guides the development of information systems. SDLC is based on a series of related activities that are combined into phases, sometimes called life-cycle phases. The phases represent a state or stage in the life of an information system. Generally speaking, an information system life cycle proceeds from requirements gathering to design and development to operations and maintenance to decommissioning. Each successive phase leverages the documentation and knowledge gained from the previous phases. Figure 2.1 shows the general flow of a basic SDLC. Figure 2.1
Basic Systems Development Life Cycle
The main purpose of using SDLC is to promote quality during the design, development, and implementation effort. When SDLC is used properly, information systems are more reliable and cost effective because project activities are planned, documented, tracked, and controlled. To ensure that the information system will meet the stated requirements, SDLC also includes predefined reviews, inspections, and audits for the life-cycle processes and deliverables to identify variances and recommend changes. Using the SDLC Acronym
As with most acronyms, there can be some confusion associated with using SDLC. Within the information technology industry, SDLC may also be used for: • Synchronous Data Link Control—A communications protocol that divides network functions into clearly defined layers. • Software development life cycle—Also known as software development process (SDP), this is the set of life-cycle phases associated with software programs. This topic will be addressed in module 3. For the purposes of this module, SDLC will be used as defined in the previous section. Why Is SDLC Important for Information Systems Development?
Information systems do not consist solely of the software and hardware an organization uses. Effective use of technology is also highly dependent on having a solid set of processes and procedures for meeting business objectives, delivering products and services, and enabling continuous process improvement. Another important component of an information system is the trained, skilled people who use the technology, processes, and procedures to operate in and manage the organization. The relationship between the technology, processes, procedures, and people is symbiotic: any change to one component will have some effect on the others. For example, introducing a new human-resources information system into an organization without considering how it might affect the organization's processes and procedures could doom the system to failure before it is fully deployed. A key aspect of using SDLC is considering all components of an information system throughout the entire project. This holistic approach is one of the main reasons why using SDLC is increasingly becoming a critical success factor for implementing today's complex, high-stakes information systems. Because implementing these systems is an expensive, multiyear effort, SDLC is also an important organizational tool to ensure that information system resources are implemented in a fiscally responsible and efficient manner. A life-cycle approach ensures that there is a clear plan and process for: • identifying and validating organizational requirements early in the project • designing and developing the system based on the approved requirements • deploying and transitioning the completed system to the user community • operating, maintaining, and updating the system once it is deployed • decommissioning the system when it is no longer...