Most organizations spend millions of dollars annually in the acquisition, design, development, implementation, and maintenance of information systems. The need for secure and reliable system solutions is easily recognized by the dependence on computer systems needed to provide products and administer daily activities.
SDLC methodology establishes policies, procedures, and guidelines managing project development, planning, requirements analysis, design, development, integration and test, implementation, and operations, maintenance, and disposition of information systems. The SDLC is not the do-all, be-all, end-all methodology. There are many permutations of it, but those concepts will not be addressed in this section. However, SDLC is one development method that has a proven track record and should be integrated with already-existing organization policies and procedures.
SDLC Benefits
Reduced risk of project failure
Consideration of user requirements throughout the system's lifetime
Early identification of technical, performance, and management issues
Description and disclosure of all costs guiding business decisions
Realistic user expectations of what the system will deliver
Identification of systems and processes that are no longer cost effective
Measurements of project progress to enable necessary corrections
Supports effective resource and budget planning and accountability
Identifies current and future business requirements
SDLC Supports the Use of an Integrated Product Team
The SDLC project team can provide for the project's success. It should be an interdisciplinary group composed of a senior management project sponsor, a project manager, and team members responsible for planning, implementation, and delivery. Team members should comprise senior employees representing business units such as user groups, human resources, program/functional management, quality assurance, security, legal, telecommunications, data administration, database administration, logistics, financial, systems engineering, test and evaluation, contracts management, audit, physical facilities, and configuration management. Working together in a proactive, open-communication, team-oriented environment can build a successful project by providing decision makers with the necessary experience and information to make the right decisions at the right time.
The SDLC has nine phases or steps that will be briefly described:
SDLC System Concept Development Phase. This project concept initiates the development lifecycle. It begins when a business need, based on operational requirements, is identified. Once the operational requirement is expressed, the approaches for meeting it are reviewed for necessity, feasibility, reasonableness, and appropriateness. The need may involve development of a new product or the modification of an existing system. Senior managers are usually the responsible officials for approvals and funding before the planning phase can begin.
Planning Phase. A program plan is developed documenting the approach to be used, including the formulation of methods, tools, resources, schedules, user input, funding, audit, and risk management.
Requirements Analysis Phase. User requirements are formally defined along with the requirements of system performance, data, risk management, and maintenance. All requirements are detailed to such a level that it is sufficient for designers to proceed.
Design Phase. The external characteristics of the system are designed during this phase. Operating environments are established, major sub-systems with their required inputs and outputs are defined. At this time, processes are allocated to resources. User input is documented, reviewed, and modified, and final approval is made. Internal characteristics of the system are described, specified, and designed. Required logic specifications are prepared for software modules.
Development Phase. Detailed specifications produced during the design phase are translated into hardware, software, and communications links. Software is integrated, tested, modified if necessary, and retested.
Integration and Test Phase. System integration, risk management, and user acceptance are conducted during this phase. Users, audit, and quality assurance units validate the functional requirements, as defined in the functional requirements documentation. It is important that these functional requirements are satisfied by the developed system.
Implementation Phase. The systems are installed and made operational initially in a test environment. After successful testing, the system is made operational in a production environment. This phase continues until the system is operating in production in conformity with user requirements and design parameters. Its security is certified. In this phase, it is accepted or rejected by users.
Operations and Maintenance Phase. By now the system is operating and is monitored for continued performance, satisfying user requirements. If needed, system modifications proceed through a requirements and necessity phase; they are scheduled, designed, tested, and implemented. If more than relatively simple modifications or changes are identified, the system will reenter the planning phase.
Disposition Phase. Disposition activities ensure the orderly review, modification, and termination of the system. Emphasis is granted to the preservation of data processed by the system in order for data to be migrated to another system or stored in compliance with records management policies, laws, or regulations for future accessing and processing.
Management Controls
The SDLC requires the following comprehensive management controls:
Structured approach to systems development, operation, and disposal
A senior management sponsor, preferably someone with a cheerleader's enthusiasm
Project management limited to a single, accountable project manager
Comprehensive project planning required for each system project
Projects proceed when sufficient resource availability is assured
Organized and accessible documentation of all steps, decisions, deliberations, agreements, requirements, plans, proposals, schedules, risk management, security measures, quality controls, funding, auditing, and meetings
Documentation
The SDLC specifies that documentation shall be generated during each phase. The principal categories of documentation are divided into two types:
1. Process documentation details actions taken for developing, implementing, testing, and maintaining the system. Process documentation includes but is not necessarily limited to plans, notes, meeting minutes, deliberations, funding, schedules, charts, funding expenditures, auditing documents, quality control decisions, reports, and time and attendance reports.
2. Product documentation includes matters that detail the system itself, what it is, how it is operated, how it is maintained, and future disposal. Examples include but are not limited to technical manuals, user manuals, operations manuals, maintenance manuals, systems requirements documentation, and design documentation.
It should be noted that some documentation will remain relatively static throughout the system lifecycle and some will be continuously changed. Some documents are revised documenting the results of analyses performed during operations. Each document should be collected, stored securely, and protected for future reference. It is important that regulatory and legal issues are addressed before any documentation is destroyed. Undocumented or inadequate documentation of decisions and events can cause significant confusion or wasted efforts and can intensify the effect of team member turnover. Activities should not be considered complete, nor decisions made, until there is sufficient documentation of the activity or decision. In the case of some very large projects, there cannot be advancement to the next SDLC phase without the required audits, management reviews, and appropriate approvals.
1 comments:
its a nice post covering important points of SDLC and SDLC Benefits
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