Software Engineering | Program Development Life Cycle (PDLC)

INTRODUCTION:

The Program Development Life Cycle (PDLC) is a process used in software engineering to manage the development of software programs. The PDLC is similar to the Software Development Life Cycle (SDLC), but is applied at a higher level, to manage the development of multiple software programs or projects.

The PDLC is typically divided into several phases, including:

• Planning: In this phase, the goals and objectives of the program are defined, and a plan is developed to achieve them. This includes identifying the resources required and determining the budget and schedule for the program.
• Analysis: In this phase, the requirements for the program are defined and analyzed. This includes identifying the stakeholders, their needs and expectations, and determining the functional and non-functional requirements for the program.
• Design: In this phase, the program’s architecture and design are developed. This includes creating a detailed design of the program’s components and interfaces, as well as determining how the program will be tested and deployed.
• Implementation: In this phase, the program is developed and coded. This includes writing the program’s source code and creating any necessary documentation.
• Testing: In this phase, the program is tested to ensure that it meets the requirements and is free of defects.
• Deployment: In this phase, the program is deployed and made available to users.
• Maintenance: After the deployment, the program is maintained by fixing any bugs or errors that are found and updating the program to meet changing requirements.

The PDLC is an iterative process that allows for feedback and adjustments to be made at each phase, to ensure that the final product meets the needs of the stakeholders and is of high quality.

Program Development Life Cycle (PDLC) is a systematic way of developing quality software. It provides an organized plan for breaking down the task of program development into manageable chunks, each of which must be successfully completed before moving on to the next phase. The program development process is divided into the steps discussed below:

1. Defining the Problem – The first step is to define the problem. In major software projects, this is a job for system analyst, who provides the results of their work to programmers in the form of a program specification. The program specification defines the data used in program, the processing that should take place while finding a solution, the format of the output and the user interface.
2. Designing the Program – Program design starts by focusing on the main goal that the program is trying to achieve and then breaking the program into manageable components, each of which contributes to this goal. This approach of program design is called top-bottom program design or modular programming. The first step involve identifying main routine, which is the one of program’s major activity. From that point, programmers try to divide the various components of the main routine into smaller parts called modules. For each module, programmer draws a conceptual plan using an appropriate program design tool to visualize how the module will do its assign job. Program Design Tools: The various program design tools are described below:
   • Structure Charts – A structure chart, also called Hierarchy chart, show top-down design of program. Each box in the structure chart indicates a task that program must accomplish. The Top module, called the Main module or Control module. For example:
   • Algorithms – An algorithm is a step-by-step description of how to arrive at a solution in the most easiest way. Algorithms are not restricted to computer world only. In fact, we use them in everyday life.
   • Flowcharts – A flowchart is a diagram that shows the logic of the program. For example:
   • Decision tables – A Decision table is a special kind of table, which is divided into four parts by a pair of horizontal and vertical lines.
   • Pseudocode – A pseudocode is another tool to describe the way to arrive at a solution. They are different from algorithm by the fact that they are expressed in program language like constructs.
3. Coding the Program – Coding the program means translating an algorithm into specific programming language. The technique of programming using only well defined control structures is known as Structured programming. Programmer must follow the language rules, violation of any rule causes error. These errors must be eliminated before going to the next step.
4. Testing and Debugging the Program – After removal of syntax errors, the program will execute. However, the output of the program may not be correct. This is because of logical error in the program. A logical error is a mistake that the programmer made while designing the solution to a problem. So the programmer must find and correct logical errors by carefully examining the program output using Test data. Syntax error and Logical error are collectively known as Bugs. The process of identifying errors and eliminating them is known as Debugging.
5. Documenting the Program – After testing, the software project is almost complete. The structure charts, pseudocodes, flowcharts and decision tables developed during the design phase become documentation for others who are associated with the software project. This phase ends by writing a manual that provides an overview of the program’s functionality, tutorials for the beginner, in-depth explanations of major program features, reference documentation of all program commands and a thorough description of the error messages generated by the program.
6. Deploying and Maintaining the Program – In the final phase, the program is deployed (installed) at the user’s site. Here also, the program is kept under watch till the user gives a green signal to it. Even after the software is completed, it needs to be maintained and evaluated regularly. In software maintenance, the programming team fixes program errors and updates the software.

ADVANTAGES OR DISADVANTAGES:

Advantages of Program Development Life Cycle (PDLC) include:

Provides a structured approach: PDLC provides a structured approach to developing software, which helps to ensure that the program is developed in a logical and organized way.

• Facilitates communication: PDLC helps to facilitate communication between different stakeholders, such as developers, project managers, and customers.
• Identifies and manages risks: PDLC helps to identify and manage potential risks during the development of the program, allowing for proactive measures to be taken to mitigate them.
• Improves quality: PDLC helps to improve the quality of the final product by providing a systematic approach to testing and quality assurance.
• Increases efficiency: By following a PDLC, the development process becomes more efficient as it allows for better planning and organization.

Disadvantages of Program Development Life Cycle (PDLC) include:

• Can be time-consuming: Following a strict PDLC can be time-consuming, and may delay the development of the program.
• Can be inflexible: The rigid structure of PDLC may not be suitable for all types of software development projects, and may limit the ability to incorporate changes or new ideas.
• Can be costly: Implementing a PDLC may require additional resources and budget, which can be costly for organizations.
• Can be complex: PDLC can be complex, and may require a certain level of expertise and knowledge to implement effectively.
• May not be suitable for smaller projects: PDLC may not be suitable for smaller projects as it can be an overkill and would not be cost-effective.

REFERENCE:

There are many books available that provide an in-depth look at the Program Development Life Cycle (PDLC) and its implementation in software engineering. Some popular books on the topic include:

• “Program Development in Java: Abstraction, Specification, and Object-Oriented Design” by Barbara Liskov and John Guttag
• “Software Engineering: A Practitioner’s Approach” by Roger Pressman
• “Program Development and Design Using Java” by Gary J. Bronson
• “Software Engineering: Principles and Practice” by Hans van Vliet
• “Programming from the Ground Up” by Jonathan Bartlett

These books provide a comprehensive overview of the PDLC and its implementation in software engineering, and are a valuable resource for developers, project managers, and other software professionals looking to improve their understanding of the topic.