Muhammad Atif Javed

A systematic literature review of traceability approaches between software architecture and source code

The links between the software architecture and the source code of a software system should be based on solid traceability mechanisms in order to effectively perform quality control and maintenance of the software system. There are several primary studies on traceability between software architecture and source code but so far no systematic literature review (SLR) has been undertaken. This study presents an SLR which has been carried out to discover the existing traceability approaches and tools between software architecture and source code, as well as the empirical evidence for these approaches, their benefits and liabilities, their relations to software architecture understanding, and issues, barriers, and challenges of the approaches. In our SLR the ACM Guide to Computing Literature has been electronically searched to accumulate the biggest share of relevant scientific bibliographic citations from the major publishers in computing. The search strategy identified 742 citations, out of which 11 have been included in our study, dated from 1999 to July, 2013, after applying our inclusion and exclusion criteria. Our SLR resulted in the identification of the current state-of-the-art of traceability approaches and tools between software architecture and source code, as well as gaps and pointers for further research. Moreover, the classification scheme developed in this paper can serve as a guide for researchers and practitioners to find a specific approach or set of approaches that is of interest to them.

Empirical evaluation of the understandability of architectural component diagrams

The architecture of a software system plays a crucial role during evolution and maintenance, as it provides the means to cope with the inherent system complexity by abstracting from implementation and design details. Architectural component models represent high level designs and are frequently used as a central view of architectural descriptions of software systems. Hence, understandability of those models is crucial as they play a key role in supporting the architectural understanding of a software system. In this paper we present the results from a study we carried out to examine to which extent the software architecture could be conveyed through architectural component diagrams. The statistical evaluation of the results shows that metrics such as the number of components, number of connectors, number of elements, and number of symbols used in the diagrams can significantly decrease architectural understandability when they are above and below a certain, roughly predicted threshold. Also, our results indicate that architectural understandability is linearly correlated with the perceived precision and general understandability of the diagrams.

The Supportive Effect of Traceability Links in Change Impact Analysis for Evolving Architectures – Two Controlled Experiments

The documentation of software architecture relations as a kind of traceability information is considered important to help people understand the consequences or ripple-effects of architecture evolution. Traceability information provides a basis for analysing and evaluating software evolution, and consequently, it can be used for tasks like reuse evaluation and improvement throughout the evolution of software. To date, however, none of the published empirical studies on software architecture traceability have examined the validity of these propositions. In this paper, we hypothesize that impact analysis of changes in software architecture can be more efficient when supported by traceability links. To test this hypothesis, we designed two controlled experiments that were conducted to investigate the influence of traceability links on the quantity and quality of retrieved assets during architecture evolution analysis. The results provide statistical evidence that a focus on architecture traceability significantly reduces the quantity of missing and incorrect assets, and increases the overall quality of architecture impact analysis for evolution.

On the effects of traceability links in differently sized software systems

Context: None of the published empirical studies on software traceability have comparatively examined the support for differently sized systems. Objective: This paper reports on two controlled experiments performed with two Enterprise Service Bus (ESB) systems that are comparable in terms of support features and system structure, but are different in their size, in particular, UltraESB Version 2.3.0 and PetalsESB Version 4.2.0, to investigate the effects of system size on the use of traceability links. Method: We conducted two controlled experiments in which the same impact evaluation activities were performed and measured how the control groups (provided with no traceability information) and the experiment groups (provided with traceability information) performed these activities in terms of the quantity and quality of retrieved elements. Results: Our findings show that the 133.71% larger size of one of ESBs does not have a significant influence on the quantity and quality of retrieved elements in the experiment groups. In the control groups, in contrast, this increase in system size significantly increases the quantity of incorrect elements and reduces the overall quality of elements retrieved, while no conclusive evidence concerning the quantity of missing elements was found. Conclusion: It is concluded that traceability is more important in larger software systems.

Cost-Effective Traceability Links for Architecture-Level Software Understanding: A Controlled Experiment

An important architectural challenge is to recover traceability links between the software architecture and artifacts produced in the other activities of the development process, such as requirements, detailed design, architectural knowledge, and implementation. This is challenging because, on the one hand, it is desirable to recover traceability links of a high quality and at the right quantity for aiding the software architect or developer, but, on the other hand, the costs and efforts spent for recovering should be as low as possible. The literature suggests manual, semi-automatic, and automatic recovery methods, each of which exhibits different impacts on costs as well as quantity and quality of the recovered links. To date, however, none of the published empirical studies have comparatively examined the automation alternatives of traceability link recovery. This paper reports on a controlled experiment that was conducted to investigate how well typical results produced by the three automation alternatives support human software developers in architecture-level understanding of the software system. The results provide statistical evidence that a focus on automated information retrieval (IR) based traceability recovery methods significantly reduces the quantity and quality of the elements retrieved by the software developers, whereas no significant differences between manual and semi-automatic traceability link recovery were found.

Towards a Framework for Detecting Containment Violations in Service Choreography

In the design and development of service oriented applications, service choreography models describe the interactions between services at different abstraction levels. These models are usually created and evolved independently by different stakeholders and consequently deviations occur among models such as message not received and incompatible behaviours. It is therefore crucial to detect and resolve the deviations before actual implementation and deployment is undertaken. This paper presents a containment checking approach that verifies whether the behaviour (or interactions) described by the local choreography models collectively encompasses those specified in the global model. Previous studies have not considered the containment relationship between global and local choreography models. The proposed approach performs automated transformation of service choreography models into formal descriptions and consistency constraints for leveraging the analytical powers of model checking techniques for the containment verification. The approach provides more informative and comprehensive feedbacks to the stakeholders for identification of containment problems and their resolutions. The applicability of the approach is demonstrated through use case scenarios of ATM machine, travel booking and order processing systems.

Towards a pattern language for construction and maintenance of software architecture traceability links

The documentation of software architecture traceability links is the foundation for many important architecture management activities, such as verification and validation, reuse evaluation and impact analysis. In practice, the construction and maintenance of traceability links is mostly manual, which is labor-intensive and error prone. Although the costs of manual traceability in terms of the time, effort and money required can be mitigated by automated construction, the completeness and correctness of traceability links tends to be negatively affected by automation in their creation and maintenance. This paper presents a pattern language for construction and maintenance of software architecture traceability links to requirements and source code. As a foundation for deriving the pattern language, we have performed systematic literature reviews, investigations of traceability links for multiple open-source software systems, and empirical studies. In particular, we studied the nature of the software architecture traceability phenomenon and its driving factors and impacts, as well as the methods that provide the means to control software architecture traceability. The derived pattern language provides support for addressing multiple decision categories for construction and maintenance of software architecture traceability links. To illustrate the patterns, their application is shown in the context of constructing and maintaining traceability links for an open source framework for mobile games.

The Impact of Hierarchies on the Architecture-Level Software Understandability - A Controlled Experiment

Architectural component models represent high level designs and are frequently used as a central view of architectural descriptions of software systems. They play a crucial role in the whole development process and in achieving the desired software qualities. This paper presents an empirical study that examines the impact of hierarchies on the architecture-level software understand ability. In particular we have studied three different architectural representations of a large-size software system, one with a hierarchical representation where architectural components at all abstraction levels in the hierarchy are shown, and two that do not contain hierarchical abstractions but concentrate only on the lowest level or on the highest level components in the hierarchy. We conducted a controlled experiment in which participants of three groups received one of the three architecture documentations plus the source code of the system and had to answer understand ability related questions. Our results show that using the hierarchical architecture leads to: 1) higher quantity of correctly retrieved elements, 2) lower quantity of incorrectly retrieved elements, and 3) higher overall quality of retrieved elements. The obtained results provide empirical evidence that hierarchies play an important role in the context of architectural component models from the viewpoint of the architecture-level software understandability.