Software Reengineering Part 2: A Process Guide for Project Success

Software reengineering aims at making your applications efficient, reliable, and maintainable, improving employee morale, customer satisfaction, and overall profitability of your business.

In part one we've understood the importance and advantages of reengineering for business success. In this part, we go over the process in detail to help you undertake the reengineering project with confidence, and succeed in this endeavor.

The Software Reengineering Process

Software reengineering is a crucial process which is time consuming and expensive. It needs to be managed sensibly with experienced skills at the helm to steer the project through its critical steps. Outlined below are the major milestones in a reengineering project — planning and assessment, reverse engineering, restructuring, forward engineering, and maintenance. Let's go through each of these steps and their sub processes in detail.

1. Planning and Assessment

Review existing documentation

It's essential to gain thorough insight into the existing system. Begin by reviewing all documentation of the software which includes requirements documents, design documents, user manuals, tech specifications, and mainly, code comments. The review will help you identify the purpose and functionality of the application and its architecture and design. You would also identify issues and get a sense of the overall quality of the documentation.

Interview stakeholders

Interview stakeholder: managers, developers, and users. Understand the current and future needs of system users, gather information related to the systems strengths and weaknesses. Outline the risks and challenges associated with the reengineering effort. Moreover, convince key stakeholders and gain support for reengineering the project.

Analyze the codebase

Identify the overall structure, and understand the code's functionality. Remember to document and communicate any potential legacy code problems with the team and management. By analyzing the code you can determine the extent of the effort required to reengineer the system.

Identify risks and challenges

Understand the scope of the project — it may be a large complex undertaking. Check if you have enough resources to complete the project: investments, human resources and the necessary infrastructure and tools. Find out if the reengineering effort aligns with the organization's overall plan — assess the plan and ensure it does not hinder current business operations.

Develop a plan to mitigate any potential risks and adjust the scope of the project if required. Further, communicate the risks to the stakeholders.

2. Reverse Engineering

Extract High-Level Design Information

Uncover the fundamental structure and organization of the software by identifying modules, classes, and components. Understand the interactions between these elements, map the data flow, and determine and document the overall architectural pattern.

Getting a clear understanding of the systems structure and functionality will help you outline areas for improvement and optimization. This step is extremely crucial for the subsequent phases of the reengineering process.

Identify Data Flows

Trace the movement of data within the software and understand how data is input, processed, stored and output. Identify data sources, sinks, and processing points, and analyze data transformation and manipulation.

Determine data storage locations and access mechanisms. Also identify any data dependencies and relationships. This will not only help you implement proper data governance and security, but will also help you identify potential bottlenecks and inefficiencies in data flow.

Understand Control Flow

Analyze the sequence of operations and decisions within the application. Begin by identifying control structures: if-else conditions, loops and switches. Study the flow of execution through the code, understand how the system handles errors, and understand how the system behaves on user interaction at a micro level.

This part is crucial to indentify flaws in the legacy system, while providing opportunities to optimize it for efficiency.

Document the Software Architecture

Capture all the extracted design information and insights in to a comprehensive architectural representation. Create UML diagrams (class, sequence and state diagrams) and develop architectural models (layered and service oriented architecture). Write detailed architectural descriptions to communicate the application's structure, components and their relationships.

Keep the documentation thorough as this would serve as a valuable reference for future study, modifications, and maintenance. Providing a clear and precise visual representation of the systems architecture not only enables identification and resolution of existing flaws, but also facilitates communication between the team members and stakeholders.

3. Restructuring

Refactor Code

Begin to modify the existing code without changing its external behavior — improve its internal structure, readability and maintainability. Remove any dead code and unused data structures you may find. Apply design patterns to enhance code structure and organization, encapsulate reusable code into functions and appropriate modules, and simplify complex expressions and algorithms. Improve naming conventions and comment your code thoroughly.

By adhering to coding standards you reduce the likelihood of introducing bugs while implementing changes, while enhancing code reusability and extensibility. This not only promotes consistency but fosters collaboration among developers.

Modularize the Codebase

This step involves organizing you code intro well-defined, independent modules. Each with its specific responsibility and limited interaction with other modules.

Identify logical boundaries between modules and encapsulate functionality into distinct modules with clear interfaces. Apply modular design patterns to promote separation f concerns and minimize dependencies between modules. Utilize dependency injection techniques to enhance flexibility.

Modularization improves code reusability and reduces duplication of effort. It reduces ripple effect during maintenance by isolating code changes. Appropriately modularizing code easy testing and debugging and also enables easier integration with external frameworks and components when required. Overall, it promotes better understanding of the system structure and functionality.

Improve Documentation

Software development is a collaborative effort. It takes a team of developers, testers and other stakeholders to build and maintain applications.

Enhance the existing documentation to provide clear and comprehensive explanation of the application's structure, functionality and design decisions taken during development. Good documentation serves as a valuable resource for team members with different level of expertise.

Consistently maintaining documentation reduces the risk of losing critical information and ensures accurate knowledge transfer when needed. It not only reduces time and effort during development, but supports future modifications and maintenance efforts as well.

Update the documentation to reflect the current state of the code, add detailed descriptions of modules, classes, and functions, and clearly explain your design decisions and the relative trade-offs. Create diagrams and flowcharts to illustrate your decisions and enhance understanding.

4. Forward engineering

Author New Code

You've gained insight while refactoring code and have put substantial effort into documenting the system. Now it's time to create new code functions, classes and modules to implement desired functionality and enhancements you require. Produce code that meets the projects objectives.

It's important to produce clean, well structured code that adheres to coding standards and appropriate design patterns. The produced code must be testable and maintainable while avoiding bugs and defects.

Adhere to coding conventions and style guides while utilizing appropriate programming languages, frameworks and libraries. Apply unit testing to ensure code functionality and correctness. Don't forget to add relevant documentation for the new code.

Add New Features

Reengineering software improves the system's adaptability to evolving requirements. It can pave the way to enhance the software's capabilities and provide value to users, and opens opportunities to expand reach, provide a competitive edge in the market, attract new users.

Introduce new functionality to the software while maintaining compatibility with the existing codebase. Careful planning in the integration stage is crucial to ensure the overall quality and stability of the system.

Gather and analyze requirements for new application features while taking into account the impact on the system. Design new features following the same standards implemented during the refactoring phase. Ensure you don't introduce conflicts or regressions. Test new features thoroughly and make sure they meet the requirements outlined earlier and to ensure it does not disrupt the systems existing functionality.

Test the New Software

Rigorously evaluate your newly developed and modified software. Ensure it meets the requirements and functions and is free from bugs and defects. Comprehensively employ testing methods to assess the software's quality and reliability.

It's essential to uncover bugs and defects in the early stages of the development cycle. Correcting software defects becomes increasingly difficult and complex as the project progresses. Make sure the software meets your users expectations and the requirements specified. Testing the application for quality, reliability and stability reduces the chances of post-deployment issues and the resulting customer dissatisfaction.

Employ automated testing tools and frameworks to streamline your testing process. Conduct unit testing to verify the correct working of individual modules. Perform integration testing to assure seamless functionality between different modules. Test your system rigorously to ensure the software meets the required functionality — check it against the requirements outlined earlier. Conduct acceptance testing, encourage user feedback and make sure the software meets the end users needs.

Testing is one of the most crucial parts of the software development cycle. Ensure you have the best skills and tools to test your applications. Businesses today prefer to outsource testing to reliable partners for high quality service.

Deploy the New Software

Introducing the newly developed or modified software into the production environment in a controlled and planned manner is vital to your project success. A well defined deployment plan can ensure a smooth transition while minimizing potential downtime. It also enables roll back mechanisms to counter any unforeseen issues.

Create a detailed plan that outlines the deployment process, timelines, and responsibilities. Communicate the deployment schedule with the respective team and stakeholders and discuss its potential impact. Perform a pre-deployment test to make certain the software is ready to be rolled out. Revert to the previous version if necessary. Monitor system performance after deployment and gain user feedback to check if the deployment has been successful.

A well planned deployment minimizes disruption to existing operations and user experience.

5. Maintenance

Fix Bugs

It's essential to diagnose, identify, and resolve software defects and bugs arising during operations. Maintain the overall quality and reliability of the application by fixing issues in a timely manner. Ensure that every aspect of the software continues to function properly and meets users expectations.

Reproduce the bugs identified during testing, and the ones reported by users. Analyze what's causing them and trace them back to the source code, modify the code to fix the bugs and prevent their recurrence. Conduct a thorough regression test to ensure the fixes you've made hasn't introduce new issues. Finally, don't forget to update the documentation to reflect the resolved bugs.

Maintaining the application's functionality, stability and reliability prevents user frustration. Defect free software protects the company's reputation and brand image while fostering user satisfaction and loyalty.

Update Documentation

Revise the existing documentation with the latest modifications and software updates. Add new documentation for any new features or functionality you may have implemented. Ensure the structure, style, and formatting is consistent throughout the documentation. Additionally, check if the documentation is easily accessible to the developers, testers, and support agents.

Remember to review and update the documentation as the project progresses.

Respond to User Feedback

User feedback provides valuable insights into the software's performance, usability and overall customer satisfaction. Gather, analyze, and respond timely to user feedback regarding the reengineered software.

Establish appropriate channels to collect user feedback. You can do this via surveys, online forums, and support tickets. Analyze the feedback for common issues, feature requests, or suggestions to improve the application. Prioritize user feedback based on the impact it would have, and the feasibility. Make sure it aligns with your business goals. Implement the changes and make improvements to your software. Communicate with the users regarding the changes or faults they've pointed out in a timely manner, and keep them posted on the progress.

It's essential to establish direct lines of communication between application users and developers. You gain customer loyalty by addressing their concerns and needs. It also fosters a customer centric and agile culture and enhances the overall value and marketability of the application.

Conclusion

Software reengineering can be a arduous and risky undertaking. It's however an initiative that can transform your application to become maintainable, efficient, reliable and adaptable to changing market demands and customer expectations.

Agile Soft Systems is a modern application development company with over ten years of experience helping businesses achieve their reengineering and modernization goals. We have an expert team of software architects, UX and UI designers, developers, and quality assurance engineers to help you at every step of your application reengineering journey.

Reach out to us to ensure software reengineering and modernization project success.

Please find the text — In part one Reengineering Legacy Software, Part 01 - The Business Advantage