Legacy Application Testing Without Documentation
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Today, legacy applications comprise more than 70% of the total corporate business systems. However, such applications are highly rigid and fragile in nature because of which most companies spend more than half of their IT budget on maintaining these legacy systems.
It is often considered a pejorative system that refers to a system that is outdated or needs replacement. It could be any system that has been inherited from an older version or is not linked to the Internet. You can also term an organization’s inactive application as a Legacy system.
Building a legacy application is no overnight task, as they are built over the years. Today, most of the organizations hold their business logic in such applications; however, the exact business process is known to very few of the employees. The situation becomes more challenging and complex, when such legacies are not documented properly. In spite of all these, most companies hesitate to upgrade their legacy applications, as they provide a longer stability.
However, even if one thinks about upgrading or replacing the legacy systems, there are tremendous risks and concerns associated with it. It requires a considerable amount of time along with a strong migration and re-engineering techniques to implement any changes. Moreover, testing and maintaining them during these situations is crucial. If there are many users involved and they do not feel the need for a drastic change, the companies consider the application to be quite stable and prefer using them.
Legacy Testing Without Documentation
Legacy applications are often delivered based on a particular business need. Such applications are not properly documented, as they may not be relevant in the future. This inefficiency adds a huge maintenance costs for many legacy systems. In some cases, even if the documents are available, they are just in the form of source code or prove to be insufficient.
There are many complications involved in testing such applications while upgrading them. Moreover, the complexity increases with no documentation. Some of the intricacies are mentioned below.
- Reduced testing capabilities and functionalities
- Lack ideas to improve the business process
- No information about the upgrades/enhancements/customizations in legacy systems
- Impact Analysis requires more time
In order to ensure a stable release of an application, there must be a well-designed Regression Suite. You can follow some of the best practices to maximize the coverage of Regression Suite.
- Prepare documents for the business process flow for the existing business
- Determine risk areas and complexities for the existing defects
- Create charts and presentations for the other’s understanding
- Analyze the effect of new changes and determine the best fit
- Try to reduce the iterative work by maintaining functional queries
- Ensure a thorough review of all the scenarios
- Unit tests can act as an initial point for documenting tests
- Use Regression testing to cover all the dependencies among functionalities of different applications
Testing Based on Dependencies
A slightest of change is enough for impacting the multiple modules or integration systems due to the blend of multiple modules and integration points. With dependency based testing, it requires minimum effort to ensure maximum coverage for the Regression Suite. In addition, it helps in the following ways:
- Understanding the interaction of different modules with each other
- Finalizing a given release with no documentation
You can always use any dependency driven testing tool to cover all the areas that might get impacted. A dependency driven testing tool can provide the following advantages:
- Cover tests with direct functionalities and any other functionality that affects the feature being tested
- Avoids the need to run the entire Regression test suite for small enhancements
- Reduces time, effort, and money
Note: User must have a detailed knowledge of the application and the changes for which the Regression Suite is built.