2.6 Software maintenance

Finally, data reverse engineering has gained in importance over the last few years where logical schemas are recovered from physical databases.

Tools

Introduction

A software maintenance tool is an artifact that supports a software maintainer in performing a task. The use of tools for software maintenance simplifies the tasks and increases efficiency and productivity.

There are several criteria for selecting the right tool for the task. These criteria are capability, features, cost/benefit, platform, programming language, ease of use, openness

of architecture, stability of vendor, and organizational culture.

Capability decides whether the tool is capable of fulfilling the task. Once it has been decided that a method can benefit from being automated, then the features of the tool need to be considered for the job.

The tool must be analyzed for the benefits it brings against its cost. The benefit indicators of a tool are quality, productivity, responsiveness, and cost reduction. The environment that the tool runs on is called the platform. The language of the source code is called the programming language. It’s important to select a tool that supports a language that is an industry standard.

The tool should have a similar feel to the ones that the users are already familiar with. The tool should have the ability to be integrated with different vendors’ tools. This will help when a tool will need to run with other tools. The openness of the architecture plays an important role when the maintenance problem is complex. Therefore, it is not always sufficient to use only one tool. There may need to be multiple tools running together.

It is also important to consider the vendor’s credibility. The vendor should be capable of supporting the tool in the future. If the vendor is not stable, the vendor could run out of business and not be able to support the tool. Another important factor is the culture of the organization. Every culture has its own work pattern. Therefore, it is important to take into consideration whether the tool is going to be accepted by the target users.

The chosen tools must support program understanding and reverse engineering, testing, configuration management, and documentation.

Selecting a tool that promotes understanding is very important in the implementation of change since a large amount of time is used to study and understand programs.

Tools for reverse engineering also accomplish the same goal. The tools mainly consist of visualization tools, which assist the programmer in drawing a model of the system.

Examples of program understanding and reverse engineering tools include the program slicer static analyzer, dynamic analyzer, cross-referencer and dependency analyzer.

Slicing is the mechanical process of marking all the sections of a program text that may influence the value of a variable at a given point in the program. Program slicing helps the programmers select and view only the parts of the program that are affected by the changes. Static analyzer is used in analyzing the different parts if the program such as modules, procedures, variables, data elements, objects and classes. A static analyzer allows general viewing of the program text and generates summaries of contents and usage of selected elements in the program text, such as variables or objects.

A dynamic analyzer could be used to analyze the program while it is executing. A data flow analyzer is a static analysis tool that allows the maintainer to track all possible data flow and control flow paths in the program. It allows analysis of the program to better outline the underlying logic of the program. It also helps display the relationship between components of the system. A cross-referencer produces information on the usage of a program. This tool helps the user focus on the parts that are affected by the change.

A dependency analyzer assists the maintainer to analyze and understand the interrelationships between entities in a program. Such a tool provides capabilities to set up and query the database of the dependencies in a program. It also provides graphical representations of the dependencies. Testing is the most time consuming and demanding task in software maintenance.

Therefore, it could benefit the most from tools. A test simulator tool helps the maintainer

to test the effects of the change in a controlled environment before implementing the change on the actual system. A test case generator produces test data that is used to test the functionality of the modified system, while a test path generator helps the maintainer to find all the data flow and control flow paths affected by the changes.

Configuration management benefits from automated tools. Configuration management and version control tools help store the objects that form the software system. A source control system is used to keep a history of the files so that versions can be tracked and the programmer can keep track of the file changes.

Commercially available products

There are numerous products on the market available for software maintenance. One type

of product is bug tracking tools, which play an important role in maintenance. Bugzilla by the Mozilla Foundation is an example of such a tool. Other bug tracking products are Test Director by Mercury Interactive, Silk Radar by Segue Software, SQA Manager by Rational software, and QA director by Compuware.

ProTeus III Expert CMMS by Eagle Technology, Inc. is a maintenance software package that lets users schedule preventative maintenance, generate automatic work orders, document equipment maintenance history, track assets and inventory, track personnel, create purchase orders, and generate reports. Microsoft Visual Source Safe is a source control system tool that is used by configuration management.

Products that are specific to programming languages are CCFinder and JAAT which

is specifically designed for JAVA programs. CCFinder identifies code clones in JAVA program. JAAT executes alias analysis for JAVA programs. For C++ programs, there is a tool called OCL query-based debugger which is a tool to debug C++ programs using queries formulated in the object constraint language.

Summary of tools

The task of software maintenance has become so vital and complex that automated support is required to do it effectively. The use of tools simplifies tasks, increase efficiency and productivity. There are numerous tools available on the market for maintenance.