Extracting business rules from COBOL: A model-based framework

Abstract

Abstract-Organizations rely on the logic embedded in their Information Systems for their daily operations. This logic implements the business rules in place in the organization, which must be continuously adapted in response to market changes. Unfortunately, this evolution implies understanding and evolving also the underlying software components enforcing those rules. This is challenging because, first, the code implementing the rules is scattered throughout the whole system and, second, most of the time documentation is poor and out-of-date. This is specially true for older systems that have been maintained and evolved for several years (even decades). In those systems, it is not even clear which business rules are enforced nor whether rules are still consistent with the current organizational policies.In this sense, the goal of this paper is to facilitate the comprehension of legacy systems (in particular COBOL-based ones) by providing a model driven reverse engineering framework able to extract and visualize the business logic embedded in them.

Dependency-Based Extraction of Conditional Statements for Understanding Business Rules

“…The framework is extended for COBOL [6], C/C++ [2], Java [7], respectively. Furthermore, Cosentino et al [4] extended the framework for COBOL programs based on the principles of Model Driven Engineering. They automatically identify variables representing outputs using the COBOL command and visualize the extracted rules at a higher abstraction level.…”

“…Understanding business rules is a tedious and errorprone activity for two main reasons [4]. First, the documentation describing the rules is typically lost, outdated, or otherwise unavailable.…”

“…When understanding computational business rules, developers must answer which of the conditional statements correspond to the computational business rules for each output of a feature. Backward program slicing [5] is used to understand business rules [2]- [4], [6], [7]. Cosentino et al [4] proposed an application of program slicing to extract statements corresponding to business rules that compute a particular variable.…”

“…Backward program slicing [5] is used to understand business rules [2]- [4], [6], [7]. Cosentino et al [4] proposed an application of program slicing to extract statements corresponding to business rules that compute a particular variable. However, they reported that the extracted statements may include conditional statements that do not correspond to the business rules.…”

“…However, they reported that the extracted statements may include conditional statements that do not correspond to the business rules. Those statements are called technical statements [4] because they frequently verify whether system resources, such as a data file or database connection, are available for executing a feature. The technical statements themselves do not affect the output directly, although they do determine if the computation is executed.…”