Often, companies face the problem of legacy software. Such software was typically developed 15 or 20 years ago by a single developer who is no longer with the company or, for example, has retired. Legacy software is hard to maintain, add new functionality to, and integrate with other software inside an organization. Furthermore, we should remember that outdated software may have security vulnerabilities or dependence on old hardware.
In this case, an organization may decide to reengineer its software. Software reengineering is the process of improving existing software (refactoring) or creating new software with the same functionality. It is made by changing the system architecture and/or the data structure, adding functionality, and updating the stack of deprecated technologies.
The first stage of software reengineering is its total review and assessment. During the life of software, market conditions, government legislation and hardware may change. Therefore, it is necessary to study the existing software very carefully, discuss with key users all the strong and weak sides of it, and gather all new wishes and requirements for the new system. This step should also include understanding of the required integration with other systems. For example, there may be a need for some notifications (emails, SMS, etc.) or data exchange with accounting, financial, production or other systems.
The assessment and analysis results should be used to choose the best software reengineering strategy. At TYMIQ, we use a customized approach to software reengineering and help you select the strategy that suits best your specific case. We can also combine several strategies in one project if the situation warrants it.
Software reengineering strategies used by TYMIQ
When it comes to modernizing a legacy software, you can use various strategies and methodologies. Each strategy serves a distinct purpose in the software reengineering process, assisting organizations in revitalizing their old systems. Let's take a look at some of the important strategies we use at TYMIQ, such as refactoring, reverse engineering, and forward engineering.
- Refactoring: Refactoring is a process for improving the structure, readability, and maintainability of software code without changing its behavior. Making tiny, incremental modifications to the software, such as deleting duplicate code, simplifying complex functions, or optimizing algorithms, is constantly required. Refactoring is especially useful when dealing with the code that is difficult to understand or modify.
- Reverse engineering: This process involves dissecting and examining the current software in order to comprehend its inner workings and architecture. When documentation is poor or non-existent, reverse engineering is vital for creating thorough documentation and gaining insights into how the software performs. It is especially useful for decoding complex legacy systems.
- Forward engineering: As opposed to reverse engineering, forward engineering focuses on constructing a new software system based on the current needs, sometimes from a previous system. It entails creating and deploying a new solution from the ground up, leveraging cutting-edge technologies and best practices. This strategy is beneficial when the existing software is out-of-date or incompatible with the current requirements.
Choosing the right strategy or a combination of them depends on the unique specifications and goals of your reengineering project. Refactoring can help enhance the code quality, reverse engineering can provide insights into the existing systems, and forward engineering can result in a new system that meets your current requirements.
Choosing the right software reengineering strategy: Refactoring
As defined in the book “Refactoring: Improving the Design of Existing Code” by Martin Fowler (Addison-Wesley Professional, 1999), "Refactoring is about improving the design of existing code. It is the process of changing a software system in such a way that it does not alter the external behavior of the code yet improves its internal structure."
Although refactoring does not offer new features or functionalities, it improves non-functional properties of the code, such as readability, complexity, maintainability, and scalability. By upgrading the internal structure of a software system, refactoring prolongs the life of the existing code and makes it easier to work with it.
The main purposes of refactoring:
- Improving the design of software
- Making the software easier to understand
- Helping find bugs
- Helping program faster
Refactoring vs. reverse and forward engineering
While refactoring does not change the code external behavior, the forward and reverse engineering strategies are used to reorganize, re-structure, or modify the existing software systems to make them more maintainable.
How should a company define that it needs full reengineering of the software system, and that refactoring can no longer help solve its ongoing problems? The decision to undertake reverse and forward engineering usually comes when the existing system has become fully inefficient and does not meet the new regulations and compliance. The full reengineering strategies are also applied when the software system requires completely updated functionality.
Choosing the right software reengineering strategy: Reverse engineering
Reverse engineering, also known as backward engineering, is the process of examining and gathering information about an existing software system for its further modernization. It involves the analysis of the system design (for example, architecture, processes, code, structure, or material), its internal components, and the business goals it was developed to meet.
By getting to the bottom and discovering the system original design, it becomes possible to not only improve it, but also solve the problem of incorrect or incomplete documentation. Reverse reengineering can also be used to identify and demonstrate intellectual property rights.
Companies may need reverse engineering for the following purposes:
- Reconstructing out-of-date or faulty software systems based on the original design analysis.
- Increasing security of the system (and thus, enhancing the user data safety) by identifying and eliminating its vulnerabilities.
- Modernizing the system according to the latest design trends and commonly accepted patterns.
Challenges of reverse engineering
The implementation of this strategy can frequently be very hard, depending on the ultimate purpose. Reverse engineering requires careful planning, the right tools and facilities, and subject-matter specialists to oversee it to be successful.
Furthermore, reverse engineering may be prohibited by laws in some countries, as they may equate it to intellectual property theft. TYMIQ is committed to upholding intellectual property rights and will not engage in reverse engineering activities if doing so would violate the law.
Choosing the right software reengineering strategy: Forward engineering
Forward engineering relates to conventional development of the same software system, but with modernized design. The process starts from scratch and uses the new business requirements to recreate the system. In this case, the requirements come before the system development, which also eliminates the risk to violate the intellectual property rights.
Companies may need forward engineering for the following purposes:
- Gaining competitive advantage in the market by brining a new system with unique design and functions.
- Increasing productivity of work by introducing a system that is familiar to the employees, but is more convenient and efficient to use.
- Creating a system that fully meets the new requirements of stakeholders and end-users.
Challenges of forward engineering
The fact that all system requirements are provided before the start of development makes forward engineering look similar to the waterfall development methodology. In this context, we talk about major flexibility constrains if something unexpected occurs during the project. It also complicates the identification and admission of errors in the system development, because all decisions on the system design are already made. While, issues that arise after the system delivery could lead to unhappy consumers and callbacks.
The main difference between reverse engineering and forward engineering
The main difference between these two strategies lies in the fact that forward engineering creates a system from a set of predefined requirements. In contrast, reverse engineering begins with the legacy system analysis and aims to extract the original requirements incorporated inside.
TYMIQ expertise in software reengineering
At TYMIQ, we approach each case individually and develop unique reengineering scenarios best fitting your business requirements. For us, it’s a priority to select the right reengineering strategy that will minimize your costs and, at the same time, bring maximum value with the modernized system. We can also combine three reengineering strategies in one project if we see the need for it.
Our team leverages modern techniques and knowledge to make the reengineering process as much effective as it is possible. For example, when working with forward engineering, we immerse the entire team that will work on the project in the intended design of the system right from the start. To make it feasible, TYMIQ applies Event Storming.
In a nutshell, Event Storming is a workshop-based approach to Domain Driven Design that brings technical and non-technical stakeholders together to explore complex business domains.
It is a great way to involve the team in analysis and architecture design. By understanding the desired outcome in advance, the team is motivated to make informed decisions rather than following someone else's algorithm. To hone our skills in this approach, we also arrange practical workshops with our team members and partners, where we practice the use of event storming and conduct retrospective sessions together.
A particular complexity of software reengineering projects represents the requirement to ensure uninterrupted operation of the current system during its migration process. Our team has sufficient experience in solving challenges like these. We also successfully deal with the projects that require total reorganization of a database or its transfer, optimization of software architecture, implementation of new functionality, and integration of third-party APIs. To read more about our software reengineering services, check out this page.
Our specialists are always open to give a free in-depth consultation on your IT challenge or intended project. Simply drop us a line at contact@tymiq.com, and we will get back to you to discuss all the available solutions.
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