What A Systems Development Life Cycle Is

Published Date: 02 Nov 2017

SDLC Although it is primarily identified with structured analysis, the system development life cycle (SDLC) describes activities and functions that systems developers typically perform, regardless of how those activities and functions fit into a particular methodology. Stages of SDLC of represents a set of general categories that show the major steps, over time, of an information systems development project. Basic SDLC At a minimum the SDLC model includes the following steps: – System Planning: formal request – System Analysis: understand the business requirement. – System Design: create a blueprint for the new system that that will satisfy all documented requirements – System Implementation: the new system is constructed. – System operation and Support: maintains and enhances the systems.

The systems development life cycle (SDLC) is a conceptual model used in project management that describes the stages involved in an information system development project, from an initial feasibility study through maintenance of the completed application. The Systems development life cycle (SDLC) is a process used by a systems analyst to develop an information system, training, and user (stakeholder) ownership. The SDLC aims to produce a high quality system that meets or exceeds customer expectations, reaches completion within time and cost estimates, works effectively and efficiently in the current and planned Information Technology infrastructure, and is inexpensive to maintain and cost-effective to enhance. The intent of a SDLC process it to help produce a product that is cost-efficient, effective, and of high quality. Once an application is created, the SDLC maps the proper deployment and decommissioning of the software once it becomes a legacy. The SDLC methodology usually contains the following stages: Analysis (requirements and design), construction, testing, release, and maintenance (response). Vera code makes it possible to integrate automated security testing into the SDLC process through use of its cloud based platform.

The real life example of system development life cycle is used everywhere e.g. offices, Banks they used SDLC in many way e.g.

1: PLANNING For example, a company may determine that to meet business and customer service needs, an email system, an accounting and payroll system, inventory and invoicing systems that support logistics, and several databases, all need to be developed. Then the company can establish the necessary timelines to accomplish the development of the necessary systems.

2: Defines what, when, who, and how the project will be carried out. This phase expands on the high-level project outline and provides a specific and detailed project definition. This phase assumes that an RFP has been prepared and distributed, a contract project development team chosen and a Project Manager appointed.

3: ANALYSIS required understanding and documenting the user's needs for the system. Documents in detail the scope, business objectives and requirements of the system. Emphasizes what the system is to do. Includes analysis of what data needs to be replicated. In this step, the team identified above works with the current and future system users to define and model the current business processes in detail. Flow-charting is a common tool used in this step of the system development cycle. This information is then analysed and a model is devised for the new system that meets the needs of the business.

4: DESIGN describes how the proposed system is to be built. The design is specific to the technical requirements the system will be required to operate in and the tools used in building the system. Impacts the build and implementation phases of the SDLC.

5: IMPLEMENTATION Prepare for and carry out the implementation of the developed system through user acceptance testing to full production. In this step, the system is created, installed, tested and rolled out with an appropriate training program. To create the system, programming can be done in the traditional manner of writing lines of code; or in the case of Lotus, it is greatly accelerated by the use of tools and templates.

SDLC starts with the analysis and definition phases, where the purpose of the software or system should be determined, the goals of what it needs to accomplish need to be established and a set of definite requirements can be developed. During the software construction or development stage, the actual engineering and writing of the application is done. The software is designed and produced, while attempting to accomplish all of the requirements that were set forth within the previous stage. Next, in the software development life cycle is the testing phase. Code produced during construction should be tested using static and dynamic analysis, as well as manual penetration testing to ensure that the application is not easily exploitable to hackers, which could result in a critical security breach. The advantage of using Vera code during this stage is that by using state of the art binary analysis (no source code required), the security posture of applications can be verified without requiring the use of any additional hardware, software, or personnel.

There are two different types of SDLC that can be used: waterfall and agile. The major difference between the two is that the waterfall process is more traditional and begins with a well thought out plan and defined set of requirements whereas agile SDLC begins with less stringent guidelines and then makes adjustments as needed throughout the process. Agile development is known for its ability to quickly translate an application that is in development to a full release at nearly any stage, making it well suited for applications that are updated frequently

Types of tools and techniques used

In data flow diagrams, the lines between "boxes" represent data that flows between components of a system. Because these only show the flow of data, they do not give an indication of sequencing. In activity diagrams, those lines are simply transitions between activities and do not represent data flow at all. They more represent the sequencing of activities and decisions. You can tell from these what order things happen in.

Computer-aided software engineering tools (CASE),

Computer-Aided Software Engineering (CASE) is the use of software tools to assist in the development and maintenance of software. Tools used to assist in this way are known as CASE Tools. A CASE tool is a computer-based product aimed at supporting one or more software engineering activities within a software development process. Computer-Aided Software Engineering tools are those software which are used in any and all phases of developing an information system, including analysis, design and programming. For example, data dictionaries and diagramming tools aid in the analysis and design phases, while application generators speed up the programming phase. CASE tools provide automated methods for designing and documenting traditional structured programming techniques. The ultimate goal of CASE is to provide a language for describing the overall system that is sufficient to generate all the necessary programs needed.

Entity relationship diagram

Entity relationship diagram Also called an entity-relationship (ER) diagram, a graphical representation of entities and their relationships to each other, typically used in computing in regard to the organization of data within databases or information systems. An entity is a piece of data-an objector concept about which data is stored. A relationship is how the data is shared between entities. There are three types of relationships between entities:

One-to-one: one instance of an entity (A) is associated with one other instance of another entity (B). For example, in a database of employees, each employee name (A) is associated with only one social security number (B). One-to-many: one instance of an entity (A) is associated with zero, one or many instances of another entity (B), but for one instance of entity B there is only one instance of entity A. For example, for a company with all employees working in one building, the building name (A) is associated with many different employees (B), but those employees all share the same singular association with entity A. Many-to-many: one instance of an entity (A) is associated with one, zero or many instances of another entity (B), and one instance of entity B is associated with one, zero or many instances of entity A. For example, for a company in which all of its employees work on multiple projects, each instance of an employee (A) is associated with many instances of a project (B), and at the same time, each instance of a project (B) has multiple employees (A) associated with it.

Decision Trees

Decision Trees are excellent tools for helping you to choose between several courses of action. They provide a highly effective structure within which you can lay out options and investigate the possible outcomes of choosing those options. They also help you to form a balanced picture of the risks and rewards associated with each possible course of action.

Structured English is the additional method which is used for overcoming the problems of the ambiguous language in stating the actions and conditions in making the decisions and formulating the procedures. The procedure is described in the narrative format using the Structured English. It doesn't show any decisions and rules but it states the rules. Structured English specifications require the analyst to identify the conditions which occur in a process and also identify the decisions which makes these conditions occur. It also forces the analyst to find alternative actions to be taken.

In this method the steps are listed in a specific order in which they are to be taken. No special signs, symbols or any other format are used for the displaying of the steps involved like those involved in the decisions tree of decision tables. Since only Structured English statements are used it becomes easy for the analyst to state the entire procedure without wasting much time. The terminologies used in Structured English consist of mostly the data names of the elements and they are stored in the Data Dictionary.

Decision tables are a precise yet compact way to model complicated logic. Decision tables, like if-then-else and switch-case statements, associate conditions with actions to perform. But, unlike the control structures found in traditional programming languages, decision tables can associate many independent conditions with several actions in an elegant way. Decision tables are typically divided into four quadrants, as shown below

Conditions

Condition alternatives

Actions

Action entries

Key drivers for analysing systems

Need for growth

Organizations are complex systems that consist of interrelated and interlocking subsystems. Changes in one part of the system have both anticipated and unanticipated consequences in other parts of the system. The systems approval is a way of thinking about the analysis and design of computer based applications. It provides a framework for visualizing the organizational and environmental factors that operate on a system. When a computer is introduced into an organization, various functions’ and dysfunction’s operate on the user as well as on the organization. Among the positive consequences are improved performance and a feeling of achievement with quality information. Among the unanticipated consequences might be a possible threat to employee’s job, a decreased morale of personnel due to back of involvement and a feeling of intimidation by users due to computer illiteracy. The analyst’s role is to remove such fears and make the system a success a Constant change is a reality in today’s business environment, and growth is one of the ways to handle it," Cope writes. After explaining how growth is measured in terms of both revenue and profit – he addresses how it can be achieved, by internal expansion (opening new stores, selling new products) and by merging or acquiring new businesses.

Company acquisition

A corporate action in which a company buys most, if not all, of the target company's ownership stakes in order to assume control of the target firm. Acquisitions are often made as part of a company's growth strategy whereby it is more beneficial to take over an existing firm's operations and niche compared to expanding on its own. Acquisitions are often paid in cash, the acquiring company's stock or a combination of both. A merger happens when two companies are combined and the resulting company takes the form of the company who bought the other company. Why does one company buy another company? In its simplest form, it is the same reason that a company buys any other asset. Why does a company buy a piece of equipment or make an investment in stock of another company? It is because they think it is a good investment and they will earn a positive return on the investment. The goal of any business in a capitalist society is to maximize shareholder wealth and buying a company that helps accomplish that goal is seen as a good thing.

Need to increase productivity

Business productivity is a very important concept for anyone who is in business. As a matter of fact, it is one of the most important things when running a business. There are many tips and ideas that people can follow in order to increase it. Working the same rate with the same outcome day in and day out will get you consistent results; however, consistent results will not get you ahead in the business world. To be successful in any work that you do, you need to be able to increase productivity when circumstances call for it. There are several things you can do that will improve your organization skills and boost your productivity on the job.

Legal requirements

Before starting a business, the legal environment of your establishment should be researched. There are many laws, rules, and regulations that must be followed to start and run your business. Almost every aspect of your business is under some form of legal ruling. Specific forms, licenses and other documentation must be filed with state and local government offices in order to begin. Without this documentation, you may be prevented from opening. It is important for you to take a close look legal business requirements.

Aspects of Business under Legal Guidelines: Major aspects of business governed by business law can be divided into the following areas: legal structure, business name, trademarks and patents, licensing and permits, contracts and legal liability.

Legal Structure: What legal structure will your business take? This decision is of primary importance because laws governing many aspects of the business vary depending on its legal structure. The four main categories are: sole proprietorship, partnership, Limited Liability Company and corporation. These four types of business entities are discussed in the chapter on "Structuring Your Business".

Business Name: Even though a business name has no magic that will guarantee success, the name is nevertheless very important to a new business. As a small business prospers and grows, the public will begin to recognize and associate the name with the product or service. There is a body of law that specifically governs the business name. For example, if a business contains anything other than the actual names of the owners, then it is classified as a "firm name" or a "fictitious name." If the legal structure of the business is a corporation, then it must be incorporated and the business name must reflect this fact. The Fictitious Business Name Statement must be filed within 30 days of the date you open your business. The statement is valid for five years. There is a fee for initial filing and a charge for renewal. The chosen business name is valid in the county where you file, and must not be similar to any other business as to mislead the public. It must not violate any federally protected names. The fictitious name must also be printed in the newspaper for four consecutive weeks. Your local newspaper may be willing to assist in this process.