Migrating Legacy Applications to ERP Solutions
The Issue
Our customer is responsible for delivering services on behalf of the UK’s major gas transportation networks. Their services are currently implemented using a CA Gen software system to process and maintain information related to millions of domestic and commercial gas supply points. Each day the system receives thousands of transactions which must be technically and functionally validated before being processed. The application must adhere to legal rules that are documented in a disparate document set which is subject to regular change.
As CA Gen is not a widely used technology, changes to the current system requires our customer to engage the services of an external software development team meaning that any change required is both costly and time consuming.
In order to reduce both the cost and the timescales of implementing changes, our customer realised that a new system, based on a widely supported, commercial off the shelf ERP technology was required. However, before a suitable technology replacement could be selected, it was imperative that a comprehensive understanding of the existing system was developed; this presented a significant number of challenges.
In addition to the many legal requirements contained in the vast documentation set, there were also a significant number of requirements, data validation and transformation rules hidden within the existing CA Gen implementation. To ensure the new implementation was functionally equivalent, these undocumented, hidden requirements and business rules had to be uncovered.
Objektum Modernization has developed powerful tools and practises for dealing with legacy application modernization issues. Based on expertise in this field, our customer engaged with Objektum Modernization to enable them to efficiently and accurately extract the requirements and business rules from their documentation set and current implementation.
The Solution
Before proposing a solution, Objektum Modernization’s technical specialists were dispatched on-site to work closely with users and experts of the existing system to fully understand the scope of the problem.
After a thorough investigation Objektum Modernization realised that there were three primary areas to be addressed and that a combination of technologies would be required to solve the problem.
Extracting Requirements from Documentation
The first issue to be resolved was how to extract the legal requirements that were distributed across multiple documents. These documents provided no navigation capability, obscure and often conflicting terms and duplication of requirements.
To address this issue, a bespoke version of Objektum Modernization’s Document Explorer was deployed with the ability to parse and link the entire document set. Automatic links were created where documents referenced each other and a dictionary of terms (abbreviations) was automatically created. Each statement was atomised and stored in a central knowledge base which could then be further analysed by business developers, software developers and program managers. Statements found to have no impact on the requirement set were easily discarded, with the remaining statements forming the basis of the new system requirements.
Extracting Requirements from the Existing Implementation
Our customer knew that many business rules had been implemented in the existing legacy applications, which were undocumented. It was critical to uncover these rules to ensure that migration to a new platform provided functional equivalence.
Objektum Modernization developed and delivered a bespoke version of the Legacy Explorer capable of parsing and understanding CA Gen syntax. Business rules are typically implemented as constructs such as conditional statements, loops and function calls; our solution employed the Legacy Explorer to automatically detect these constructs, mark them as candidate rules and store them in the same central knowledge base along with the requirements extracted from the documents.
Business Rules Explorer
Our Business Rules Explorer is fully integrated with our central knowledge base, the Legacy Explorer for rapid extraction of information from the application source code, as well as the Document Explorer for the elicitation of requirements from project documentation. This proved the perfect tool to deploy given our clients project needs. Objektum Modernization’s development team implemented additional functionality to allow traceability links to be created between requirements extracted from the documentation, statements extracted from the source code and the business rules to be implemented in the new application. This provided project managers with a powerful traceability report showing progress and how the legacy application could be mapped to the new target platform.
On this particular engagement, the client required that all requirements, business rules and the links between them were stored in IBM Rational Requirements Composer (RRC). The Business Rule Explorer has extensive export facilities which were enhanced to fully support exporting using the RRC interface, whilst maintaining the integrity of all the artefacts and the connections between them.
The Business Rules Explorer provided a common environment where requirements and business rules could be searched, filtered, validated and organised in an efficient and scalable way. It provided users, with varying responsibilities, with a fully navigable environment that facilitated communication between business stakeholders and development teams.
Training
To ensure that everyone involved in the project followed a consistent approach to both process and toolset usage, Objektum developed a comprehensive training program. This program was rolled out on-site for all team members taking a workshop style approach, where attendees were invited to suggest improvement that were fed back. This activity ensured that everyone worked in common way and promoted a common open communication ethos, resulting in updates to both the processes and tools and streamlined the work flow.
The Outcome
Through the use of our highly automated approach, our technology and expertise, our customer was able to accelerate the extraction of requirements and business rules from a vast range of documentation and the legacy application. These were all recorded in a central knowledge base and exported to IBM Rational Requirements Composer. Our customer now has a deep understanding of their existing application, what must be implemented in the new application and feels confident that key business capabilities are preserved during the application modernization phase.
We experienced significant benefits such as:
- Dramatic time and cost savings - when compared to a manual extraction and linking activity
- Existing workflow integration - ability to interface with third-party requirements management tools such as IBM Rational Requirements Composer (RRC)
- Gap analysis - discovery of which requirements which are hidden deep within the existing legacy application
- Validation rule extraction - insight into where validation rules are implemented in the legacy source code, but are undocumented
- Ongoing maintenance capability - instant visibility (impact) on the legacy source code when a requirement changes
Objektum Modernization was also able to add value to the maintenance of the existing system by increasing our customers’ ability to respond to ongoing change in requirements.