The Systems Development Life Cycle

The Systems Development Life Cycle is the process of understanding how an information system can meet the business needs by designing a system, implementing it, and deploy it to end users. Developing software systems may seem straightforward at first, but in reality it can get complex and costly. Unfortunately, the rate of failure in software development projects is high. Many software projects delivery is later than planned and cost more than expected. Many projects are abandoned or delivered with fewer feature than specified at initiation of the project. To achieve more success rate in software development projects we should consider any new information development project as an investment, similar to any other investments and using standard practices and methodologies, increase the chance of success of the new investment.

Building a new information system or software product is similar to constructing a new building. At first the idea of building a new building is considered. Secondly the idea is analyzed and the requirements are researched and initial models are created, until the scope and features of the building is determined. The third step is designing the building in details and producing drawings and blueprints. Finally the construction is performed based on these design drawings and blueprints.

The Systems Development Life Cycle has also five fundamental phases: planning, analysis, design, implementation, and maintenance. Each phase composed of a series of steps and produce deliverables. In many projects, the Systems Development Life Cycle phases and steps are in a logical path from start to finish. In other projects the process moves through steps consecutively, incrementally, iteratively, or other patterns. But no matter what methodology is used, these five basic phases is present in every project.

In this post we discus these five phases of systems development life cycle and common. steps in every phases.

Planning

The planning phase is the initial phase of verifying the necessity of developing a new information system, and determining the process of building and the organizing the required team. This phase has two steps:

1. Project Initiation. In this step the gains of the new system for organization is identified. For example how the new system decreases the cost or increases the revenue or maybe it will increase the value of the organization non-financially. Most ideas for new systems come from Information System area in the form of information request. A system request represents a brief summary of a business need, and explains how the system that supports the need will create business value. The IS department works together with the person or department that generated the request to conduct a feasibility analysis. The feasibility analysis examines key aspects of the proposed project including, technical feasibility, economic feasibility, and organizational feasibility. The system request and feasibility analysis are presented to an approval committee, which decides whether the project should be undertaken.
2. Once the project is approved, it enters project management. During project management, the project manager creates a work plan, staffs the project, and puts methodologies for the project to go forward, The deliverable for this step is a project plan, which describes how the project team will go about developing the system.

Analysis 

In analysis phase, the project team investigates any current systems, identifies opportunities, and develops a concept design for the new system.  This phase has three steps:

1.  An analysis strategy is developed. This strategy usually includes an analysis of the current system (system-as-is) and its problems and then options to design the a new system (system-to-be).
2. The next step is requirements elicitation. The analysis of this information leads to design of a concept for the system. The system concept is used then to produce business analysis models, which describes how the organization operates using the new system.
3. The analysis, system concept, and models are combined into a document that is called system proposal.

Design

The design phase determines the operation, hardware and software needs, user interaction and other aspects of the system in detail. Although most of the important decisions about the system is made during the analysis phase, the steps in this phase determines exactly how the system will operate. The design phase has four steps:

1. The design strategy is first developed. It clarifies whether the system will be developed by the company's own programmers, by third party, or maybe buying an existing software.
2. The basic architectural design is developed. 
3. The database and file specifications are developed. The interface design specifies how the users will interact with the system.
   
4. The analyst team develops the program design, which defines the program that need to be written and exactly what each program will do.

The deliverables in this phase including, architecture design, interface design, database and file specifications, and program design is what is use by programming team to implement the system. At the end of the design phase, the feasibility analysis and project plan are revised, and if approved by project sponsor and committee the continuation of the project is decided.

Implementation

In implementation phase the system is actually built. This phase is in most projects the most expensive and longest production phase. This phase has three steps:

1. System construction is the first step. The system is built and tested to ensure if performs as designed.
2. The system is installed. The installation is the process of substituting the old system with new system.
3. The analyst team establishes a maintenance plan for the system.

After completing the building the new system, and the system is deployed for production use, it enters the maintenance phase.

Maintenance

All software systems need maintenance. New business needs should be addressed and technologies are evolving rapidly. The maintenance phase is where the software is monitored to ensure it continues to function as it was designed to, and repairs or upgrades are performed as needed. After the software is released into production, updates or upgrades will need to be made.