Lesson 3

• A program development life cycle (PDLC) is a systematic process or methodology that is used to manage the development of quality software applications in any programming language.
• PDLC Phases

  Phase 1: Problem Definition and Analysis

  Phase 2: Program Design

  Phase 3: Coding & Debugging the Program

  Phase 4: Testing & Debugging the Program

  Phase 5: Documentation

  Phase 6: Deployment & Maintenance
• Phase 1: Problem Definition and Analysis

  ▪ Identify and understand the problem statement or task that the software application needs to address.

  ▪ Break down the problem into smaller tasks and components. ▪Analyze requirements, constraints, and user expectations.

  ▪ Create a development roadmap, including list of activities and deadlines.
• Phase 2: Program Design

  • Design the program using common types of program design tools:
  • Algorithm
  • Pseudocode
  • Flowchart
• An Algorithm is a step-by-step process, or instructions used to solve a problem in the simplest way. Algorithms are not limited to the realm of computers only where we make use of them in our everyday lives.
• Characteristics of Algorithm

  • Clear / Unambiguous
  • Well-Defined Inputs and Outputs
  • Finite
  • Effectiveness
  • Deterministic
  • Generality
  • Modularity
• A pseudocode is an informal way to express algorithms using a combination of human-readable programming language-like constructs and natural language descriptions. It provides a high-level description of the algorithm's logic without getting into the specifics of actual programming syntax.
• Characteristics of Pseudocode

  • Readability
  • Flexibility / Language-agnostic
  • Clarity / Focus on Logic
• What is in the picture?

  A) Example Algorithm

  
• What is in the picture?

  A) Example Pseudocode

  
• A flowchart is a visual representation of the logic sequence of steps in solving a given problem. It uses standardized symbols and arrows to depict the flow of control in a clear and easily understandable manner. Flowcharts are widely used to visualize complex processes, algorithms, and workflows
• Fill in the Blanks

  A) Terminal

  B) Input/Output

  C) Process

  D) Decision

  
• Fill the Blanks

  A) Flow Arrow

  B) On-Page Connector

  C) Off-Page Connector

  
• Terminal - A symbol represents the BEGIN and END of the logic flow.
• Input/Output - A symbol represents the INPUT and OUTPUT of data.
• Process - A symbol represents a specific task, action, or operation.
• Decision - A symbol represents decision making between two alternatives, where the answer is Yes or No.
• Flow Arrow - A line to connect other symbols to show the flow control.
• On-Page Connector - A symbol used to connect different parts of a flowchart within the same page.
• Off-Page Connector - A symbol used to connect different parts of a flowchart that are in different page.
• Guidelines of Flowchart

  • For every flowchart, there are only two (2) terminal symbols, one for begin and one for end.
  • The common flow of the flowchart process is from top to bottom or left to right.
  • Arrows should not cross or overlap with each other.
  • Each symbol only has one incoming and outgoing flow arrow, except for the terminal, connectors and decision symbols.
  • The decision symbol has two (2) outgoing flow arrows
• Flowchart Considerations

  • Clarity
  • Simplicity
  • Consistency
  • Testing
• Benefits of Flowchart

  • Visual Representation
  • Clarity
  • Communication
  • Analysis
  • Documentation
• What is in the picture?

  A) Example Flowchart

  
• Phase 3: Coding & Debugging the Program

  • Write the actual program using any programming languages.
  • Follow the language rules to eliminate syntax errors, which occur when the rules of programming languages are violated, such as improper structure, misspellings, incorrect punctuation, etc.
  • Observe coding best practices such as readability, modularity, and comments.
• Phase 4: Testing & Debugging the Program

  • Conduct a series of tests, such as alpha testing (internally) and beta testing (externally), using test cases or various scenarios to determine if the program provides a desired output.
  • Debug the program once errors have been found, such as logic errors, a type of error where the program does not crash but produces incorrect results.
• Phase 5: Documentation

  Write a clear and comprehensive document or manual that includes an overview of the program, specifications or functionalities, user guidelines or tutorials on how to use the program, a significant explanation of program codes and commands, and operational procedures.
• Phase 6: Deployment & Maintenance

  • Deploy the program to the intended environment.
  • Monitor the performance of the program and evaluate it regularly.
  • Provide updates or improvements/enhancements of the program based on user feedback or new requirements or fix some program errors.
• Benefits of PDLC

  • Structured Development
  • Quality Assurance
  • Increase Efficiency
• A programming logic is the foundation of writing an effective and efficient code, where it involves a better understanding of how to structure your thoughts and translate them from algorithms into instructions that can be executed by the computer.
• Key Concepts in Programming Logic

  • Variables and Data Types
  • Control Structures
  • Arithmetic and Logical Operators
  • Functions and Procedures
  • Data Structures
  • Error Handling
  • Algorithm Design
• Structured Development:

  • PDLC provides a clear, step-by-step framework to develop software systematically.
  • It ensures that tasks are organized, reducing confusion and errors.
• Quality Assurance:

  • Helps in identifying and fixing errors early in the development process.
  • Ensures the final product meets user requirements and works reliably.
• Increase Efficiency:

  • Streamlines development processes, saving time and resources.
  • Improves productivity by following a well-defined workflow.
• Visual Representation:

  • Flowcharts provide a clear visual overview of processes, making it easier to understand complex workflows.
• Clarity:

  • They simplify complicated processes by breaking them into smaller, more understandable steps.
• Communication:

  • Flowcharts are a universal tool to communicate ideas, ensuring that everyone involved understands the process.
• Analysis:

  • They help identify inefficiencies, errors, or areas for improvement in a process.
• Documentation:

  • Flowcharts serve as a formal record of processes, aiding in training and future reference.
• Clarity:

  • Ensure the flowchart is easy to read and understand, avoiding overly complex designs.