A pilot study to compare programming effort for two parallel programming models

Context

Writing software for the current generation of parallel systems requires significant programmer effort, and the community is seeking alternatives that reduce effort while still achieving good performance.

Objective

Measure the effect of parallel programming models (message-passing vs. PRAM-like) on programmer effort.

Design, setting, and subjects

One group of subjects implemented sparse-matrix dense-vector multiplication using message-passing (MPI), and a second group solved the same problem using a PRAM-like model (XMTC). The subjects were students in two graduate-level classes: one class was taught MPI and the other was taught XMTC.

Main outcome measures

Development time, program correctness.

Results

Mean XMTC development time was 4.8 h less than mean MPI development time (95% confidence interval, 2.0-7.7), a 46% reduction. XMTC programs were more likely to be correct, but the difference in correctness rates was not statistically significant (p = .16).

Conclusions

XMTC solutions for this particular problem required less effort than MPI equivalents, but further studies are necessary which examine different types of problems and different levels of programmer experience.     

The impact of inadequate customer collaboration on self-organizing Agile teams

Context

Customer collaboration is a vital feature of Agile software development.

Objective

This article addresses the importance of adequate customer involvement on Agile projects, and the impact of different levels of customer involvement on real-life Agile projects.

Method

We conducted a Grounded Theory study involving 30 Agile practitioners from 16 software development organizations in New Zealand and India, over a period of 3 years.

Results

We discovered that Lack of Customer Involvement was one of the biggest challenges faced by Agile teams. Customers were not as involved on these Agile projects as Agile methods demand. We describe the causes of inadequate customer collaboration, its adverse consequences on self-organizing Agile teams, and Agile Undercover — a set of strategies used by the teams to practice Agile despite insufficient or ineffective customer involvement.

Conclusion

Customer involvement is important on Agile projects. Inadequate customer involvement causes adverse problems for Agile teams. The Agile Undercover strategies we’ve identified can assist Agile teams facing similar lack of customer involvement.     

Beyond the customer: Opening the agile systems development process

Context

A particular strength of agile systems development approaches is that they encourage a move away from ‘introverted’ development, involving the customer in all areas of development, leading to more innovative and hence more valuable information system. However, a move toward open innovation requires a focus that goes beyond a single customer representative, involving a broader range of stakeholders, both inside and outside the organisation in a continuous, systematic way.

Objective

This paper provides an in-depth discussion of the applicability and implications of open innovation in an agile environment.

Method

We draw on two illustrative cases from industry.

Results

We highlight some distinct problems that arose when two project teams tried to combine agile and open innovation principles. For example, openness is often compromised by a perceived competitive element and lack of transparency between business units. In addition, minimal documentation often reduce effective knowledge transfer while the use of short iterations, stand-up meetings and presence of on-site customer reduce the amount of time for sharing ideas outside the team.

Conclusion

A clear understanding of the inter- and intra-organisational applicability and implications of open innovation in agile systems development is required to address key challenges for research and practice.     

Conceptual scheduling model and optimized release scheduling for agile environments

Context

Release scheduling deals with the selection and assignment of deliverable features to a sequence of consecutive product deliveries while several constraints are fulfilled. Although agile software development represents a major approach to software engineering, there is no well-established conceptual definition and sound methodological support of agile release scheduling.

Objective

To propose a solution, we present, (1) a conceptual model for agile scheduling, and (2) a novel multiple knapsack-based optimization model with (3) a branch-and-bound optimization algorithm for agile release scheduling.

Method

To evaluate our model simulations were carried out seven real life and several generated data sets.

Results

The developed algorithm strives to prevent resource overload and resource underload, and mitigates risks of delivery slippage.

Conclusion

The results of the experiment suggest that this approach can provide optimized semi-automatic release schedule generations and more informed and established decisions utilizing what-if-analysis on the fly to tailor the best schedule for the specific project context.     

Conducting a Business Ethnography in Global Software Development projects of small German enterprises

Context

Studying work practices in the context of Global Software Development (GSD) projects entails multiple opportunities and challenges for the researchers. Understanding and tackling these challenges requires a careful and rigor application of research methods.

Objective

We want to contribute to the understanding of the challenges of studying GSD by reflecting on several obstacles we had to deal with when conducting ethnographically-informed research on offshoring in German small to medium-sized enterprises.

Method

The material for this paper is based on reflections and field notes from two research projects: an exploratory ethnographic field study, and a study that was framed as a Business Ethnography. For the analysis, we took a Grounded Theory-oriented coding and analysis approach in order to identify issues and challenges documented in our research notes.

Results

We introduce the concept of Business Ethnography and discuss our experiences of adapting and implementing this action research concept for our study. We identify and discuss three primary issues: understanding complex global work practices from a local perspective, adapting to changing interests of the participants, and dealing with micro-political frictions between the cooperating sites.

Conclusions

We identify common interests between the researchers and the companies as a challenge and chance for studies on offshoring. Building on our experiences from the field, we argue for an active conceptualization of struggles and conflicts in the field as well as for extending the role of the ethnographer to that of a learning mediator.     

A profiling method by PCB hooking and its application for memory fault detection in embedded system operational test

Context

An operational test means a system test that examines whether or not all software or hardware components comply with the requirements given to a system which is deployed in an operational environment.

Objective

It is a necessary lightweight-profiling method for embedded systems with severe resource restrictions to conduct operational testing.

Method

We focus on the Process Control Block as the optimal location to monitor the execution of all processes. We propose a profiling method to collect the runtime execution information of the processes without interrupting the system’s operational environment by hacking the Process Control Block information. Based on the proposed method applied to detect runtime memory faults, we develop the operational testing tool AMOS v1.0 which is currently being used in the automobile industry.

Results

An industrial field study on 23 models of car-infotainment systems revealed a total of 519 memory faults while only slowing down the system by 0.084-0.132×. We conducted a comparative analysis on representative runtime memory fault detection tools. This analysis result shows our proposed method that has relatively low overhead meets the requirements for operational testing, while other methods failed to satisfy the operational test conditions.

Conclusion

We conclude that a lightweight-profiling method for embedded system operational testing can be built around the Process Control Block.     

Research synthesis in software engineering: A tertiary study

Context

Comparing and contrasting evidence from multiple studies is necessary to build knowledge and reach conclusions about the empirical support for a phenomenon. Therefore, research synthesis is at the center of the scientific enterprise in the software engineering discipline.

Objective

The objective of this article is to contribute to a better understanding of the challenges in synthesizing software engineering research and their implications for the progress of research and practice.

Method

A tertiary study of journal articles and full proceedings papers from the inception of evidence-based software engineering was performed to assess the types and methods of research synthesis in systematic reviews in software engineering.

Results

As many as half of the 49 reviews included in the study did not contain any synthesis. Of the studies that did contain synthesis, two thirds performed a narrative or a thematic synthesis. Only a few studies adequately demonstrated a robust, academic approach to research synthesis.

Conclusion

We concluded that, despite the focus on systematic reviews, there is limited attention paid to research synthesis in software engineering. This trend needs to change and a repertoire of synthesis methods needs to be an integral part of systematic reviews to increase their significance and utility for research and practice.     

Exploring a Bayesian and linear approach to requirements traceability

Context

For large software projects it is important to have some traceability between artefacts from different phases (e.g.requirements, designs, code), and between artefacts and the involved developers. However, if the capturing of traceability information during the project is felt as laborious to developers, they will often be sloppy in registering the relevant traceability links so that the information is incomplete. This makes automated tool-based collection of traceability links a tempting alternative, but this has the opposite challenge of generating too many potential trace relationships, not all of which are equally relevant.

Objective

This paper evaluates how to rank such auto-generated trace relationships.

Method

We present two approaches for such a ranking: a Bayesian technique and a linear inference technique. Both techniques depend on the interaction event trails left behind by collaborating developers while working within a development tool.

Results

The outcome of a preliminary study suggest the advantage of the linear approach, we also explore the challenges and potentials of the two techniques.

Conclusion

The advantage of the two techniques is that they can be used to provide traceability insights that are contextual and would have been much more difficult to capture manually. We also present some key lessons learnt during this research.     

Discriminative effect of user influence and user responsibility on information system development processes and project management

Context

User participation in information system (IS) development has received much research attention. However, prior empirical research regarding the effect of user participation on IS success is inconclusive. This might be because previous studies overlook the effect of the particular components of user participation and other possible mediating factors.

Objective

The objective of this study is to empirically examine how user influence and user responsibility affect IS project performance. We inspect whether user influence and user responsibility improve the quality of the IS development process and in turn leads to project success, or if they have a direct positive influence on project success.

Method

We conducted a survey of 151 IS project managers in order to understand the impact of user influence and user responsibility on IS project performance. Regression analysis was conducted to assess the relationship among user influence, user responsibility, organizational technology learning, project control, user-developer interaction, and IS project management performance.

Results

This study shows that user responsibility and user influence have a positive effect on project performance through the promotion of IS development processes as mediators, including organizational technology learning, project control, and user-IS interaction.

Conclusion

Our results suggest that user responsibility and user influence respectively play an important role in indirectly and directly impacting project management performance. Results of the analysis imply that organizations and project managers should use both user participation and user influence to improve processes performance, and in turn, increase project success.     

Migration of information systems in the Italian industry: A state of the practice survey

Context

Software migration—and in particular migration towards the Web and towards distributed architectures—is a challenging and complex activity, and has been particularly relevant in recent years, due to the large number of migration projects the industry had to face off because of the increasing pervasiveness of the Web and of mobile devices.

Objective

This paper reports a survey aimed at identifying the state-of-the-practice of the Italian industry for what concerns the previous experiences in software migration projects—specifically concerning information systems—the adopted tools and the emerging needs and problems.

Method

The study has been carried out among 59 Italian Information Technology companies, and for each company a representative person had to answer an on-line questionnaire concerning migration experiences, pieces of technology involved in migration projects, adopted tools, and problems occurred during the project.

Results

Indicate that migration—especially towards the Web—is highly relevant for Italian IT companies, and that companies tend to increasingly adopt free and open source solutions rather than commercial ones. Results also indicate that the adoption of specific tools for migration is still very limited, either because of the lack of skills and knowledge, or due to the lack of mature and adequate options.

Conclusions

Findings from this survey suggest the need for further technology transfer between academia and industry for the purpose of favoring the adoption of software migration techniques and tools.     

Using mapping studies as the basis for further research - A participant-observer case study

Context

We are strong advocates of evidence-based software engineering (EBSE) in general and systematic literature reviews (SLRs) in particular. We believe it is essential that the SLR methodology is used constructively to support software engineering research.

Objective

This study aims to assess the value of mapping studies which are a form of SLR that aims to identify and categorise the available research on a broad software engineering topic.

Method

We used a multi-case, participant-observer case study using five examples of studies that were based on preceding mapping studies. We also validated our results by contacting two other researchers who had undertaken studies based on preceding mapping studies and by assessing review comments related to our follow-on studies.

Results

Our original case study identified 11 unique benefits that can accrue from basing research on a preceding mapping study of which only two were case specific. We also identified nine problems associated with using preceding mapping studies of which two were case specific. These results were consistent with the information obtained from the validation activities. We did not find an example of an independent research group making use of a mapping study produced by other researchers.

Conclusion

Mapping studies can save time and effort for researchers and provide baselines to assist new research efforts. However, they must be of high quality in terms of completeness and rigour if they are to be a reliable basis for follow-on research.     

Cross-domain probabilistic inference in a clinical decision support system: examples for dermatology and rheumatology

Introduction

Maintaining a large diagnostic knowledge base (KB) is a demanding task for any person or organization. Future clinical decision support system (CDSS) may rely on multiple, smaller and more focused KBs developed and maintained at different locations that work together seamlessly. A cross-domain inference tool has great clinical import and utility.

Methods

We developed a modified multi-membership Bayes formulation to facilitate the cross-domain probabilistic inferencing among KBs with overlapping diseases. Two KBs developed for evaluation were non-infectious generalized blistering diseases (GBD) and autoimmune diseases (AID). After the KBs were finalized, they were evaluated separately for validity.

Result

Ten cases from medical journal case reports were used to evaluate this “cross-domain” inference across the two KBs. The resultant non-error rate (NER) was 90%, and the average of probabilities assigned to the correct diagnosis (AVP) was 64.8% for cross-domain consultations.

Conclusion

A novel formulation is now available to deal with problems occurring in a clinical diagnostic decision support system with multi-domain KBs. The utilization of this formulation will help in the development of more integrated KBs with greater focused knowledge domains.     

Identifying refactoring opportunities in process model repositories

Context

In order to ensure high quality of a process model repository, refactoring operations can be applied to correct anti-patterns, such as overlap of process models, inconsistent labeling of activities and overly complex models. However, if a process model collection is created and maintained by different people over a longer period of time, manual detection of such refactoring opportunities becomes difficult, simply due to the number of processes in the repository. Consequently, there is a need for techniques to detect refactoring opportunities automatically.

Objective

This paper proposes a technique for automatically detecting refactoring opportunities.

Method

We developed the technique based on metrics that can be used to measure the consistency of activity labels as well as the extent to which processes overlap and the type of overlap that they have. We evaluated it, by applying it to two large process model repositories.

Results

The evaluation shows that the technique can be used to pinpoint the approximate location of three types of refactoring opportunities with high precision and recall and of one type of refactoring opportunity with high recall, but low precision.

Conclusion

We conclude that the technique presented in this paper can be used in practice to automatically detect a number of anti-patterns that can be corrected by refactoring.     

Software process improvement success factors for small and medium Web companies: A qualitative study

Context

The context of this research is software process improvement (SPI) in small and medium Web companies.

Objective

The primary objective of this paper is to identify software process improvement (SPI) success factors for small and medium Web companies.

Method

To achieve this goal, we conducted semi-structured, open-ended interviews with 21 participants representing 11 different companies in Pakistan, and analyzed the data qualitatively using the Glaserian strand of grounded theory research procedures. The key steps of these procedures that were employed in this research included open coding, focused coding, theoretical coding, theoretical sampling, constant comparison, and scaling up.

Results

An initial framework of key SPI success factors for small and medium Web companies was proposed, which can be of use for small and medium Web companies engaged in SPI. The paper also differentiates between small and medium Web companies and analyzes crucial SPI requirements for companies operating in the Web development domain.

Conclusion

The results of this work, in particular the use of qualitative techniques - allowed us to obtain rich insight into SPI success factors for small and medium Web companies. Future work comprises the validation of the SPI success factors with small and medium Web companies.     

Code churn estimation using organisational and code metrics: An experimental comparison

Context

Source code revision control systems contain vast amounts of data that can be exploited for various purposes. For example, the data can be used as a base for estimating future code maintenance effort in order to plan software maintenance activities. Previous work has extensively studied the use of metrics extracted from object-oriented source code to estimate future coding effort. In comparison, the use of other types of metrics for this purpose has received significantly less attention.

Objective

This paper applies machine learning techniques to unveil predictors of yearly cumulative code churn of software projects on the basis of metrics extracted from revision control systems.

Method

The study is based on a collection of object-oriented code metrics, XML code metrics, and organisational metrics. Several models are constructed with different subsets of these metrics. The predictive power of these models is analysed based on a dataset extracted from eight open-source projects.

Results

The study shows that a code churn estimation model built purely with organisational metrics is superior to one built purely with code metrics. However, a combined model provides the highest predictive power.

Conclusion

The results suggest that code metrics in general, and XML metrics in particular, are complementary to organisational metrics for the purpose of estimating code churn.     

Reliability analysis and optimal version-updating for open source software

Context

Although reliability is a major concern of most open source projects, research on this problem has attracted attention only recently. In addition, the optimal version-dating for open source software considering its special properties is not yet discussed.

Objective

In this paper, the reliability analysis and optimal version-updating for open source software are studied.

Method

A modified non-homogeneous Poisson process model is developed for open source software reliability modeling and analysis. Based on this model, optimal version-updating for open source software is investigated as well. In the decision process, the rapid release strategy and the level of reliability are the two most important factors. However, they are essentially contradicting with each other. In order to consider these two conflicting factors simultaneously, a new decision model based on multi-attribute utility theory is proposed.

Results

Our models are tested on the real world data sets from two famous open source projects: Apache and GNOME. It is found that traditional software reliability models provide overestimations of the reliability of open source software. In addition, the proposed decision model can help management to make a rational decision on the optimal version-updating for open source software.

Conclusion

Empirical results reveal that the proposed model for open source software reliability can describe the failure process more accurately. Furthermore, it can be seen that the proposed decision model can assist management to appropriately determine the optimal version-update time for open source software.     

Applying agglomerative hierarchical clustering algorithms to component identification for legacy systems

Context

Component identification, the process of evolving legacy system into finely organized component-based software systems, is a critical part of software reengineering. Currently, many component identification approaches have been developed based on agglomerative hierarchical clustering algorithms. However, there is a lack of thorough investigation on which algorithm is appropriate for component identification.

Objective

This paper focuses on analyzing agglomerative hierarchical clustering algorithms in software reengineering, and then identifying their respective strengths and weaknesses in order to apply them effectively for future practical applications.

Method

A series of experiments were conducted for 18 clustering strategies combined according to various similarity measures, weighting schemes and linkage methods. Eleven subject systems with different application domains and source code sizes were used in the experiments. The component identification results are evaluated by the proposed size, coupling and cohesion criteria.

Results

The experimental results suggested that the employed similarity measures, weighting schemes and linkage methods can have various effects on component identification results with respect to the proposed size, coupling and cohesion criteria, so the hierarchical clustering algorithms produced quite different clustering results.

Conclusions

According to the experimental results, it can be concluded that it is difficult to produce perfectly satisfactory results for a given clustering algorithm. Nevertheless, these algorithms demonstrated varied capabilities to identify components with respect to the proposed size, coupling and cohesion criteria.     

Contribution-based call stack abstraction for call string based pointer analysis

Context

Different method calls may have different contributions to the precision of the final application when abstracted into the call strings. The existing call string based pointer analysis algorithms do not consider such contribution difference and hence may not achieve best cost-effectiveness.

Objective

To be more cost-effective, we try to leverage the contribution information of each method call in call string based pointer analysis.

Method

The paper firstly proposes a contribution-based call stack abstraction method which abstracts the call stacks into call strings with the contribution information under consideration. Then, we apply the new call stack abstraction method to the pointer analysis of AspectJ programs and propose a concern-sensitive points-to analysis method. Besides, the new abstraction method is also applied to multi-threaded Java programs and results in a thread-sensitive pointer analysis method.

Results

The experimental results show that the two pointer analysis methods with contribution-based call stack abstraction can be more cost-effective than the ordinary call string based approaches for an application that detects harmful advices and an application that detects inter-thread data flow.

Conclusion

These pointer analysis methods more concretely and more clearly show that the contribution-based call stack abstraction can lead to better cost-effectiveness for the given applications.     

Usability evaluation methods for the web: A systematic mapping study

Context

In recent years, many usability evaluation methods (UEMs) have been employed to evaluate Web applications. However, many of these applications still do not meet most customers’ usability expectations and many companies have folded as a result of not considering Web usability issues. No studies currently exist with regard to either the use of usability evaluation methods for the Web or the benefits they bring.

Objective

The objective of this paper is to summarize the current knowledge that is available as regards the usability evaluation methods (UEMs) that have been employed to evaluate Web applications over the last 14 years.

Method

A systematic mapping study was performed to assess the UEMs that have been used by researchers to evaluate Web applications and their relation to the Web development process. Systematic mapping studies are useful for categorizing and summarizing the existing information concerning a research question in an unbiased manner.

Results

The results show that around 39% of the papers reviewed reported the use of evaluation methods that had been specifically crafted for the Web. The results also show that the type of method most widely used was that of User Testing. The results identify several research gaps, such as the fact that around 90% of the studies applied evaluations during the implementation phase of the Web application development, which is the most costly phase in which to perform changes. A list of the UEMs that were found is also provided in order to guide novice usability practitioners.

Conclusions

From an initial set of 2703 papers, a total of 206 research papers were selected for the mapping study. The results obtained allowed us to reach conclusions concerning the state-of-the-art of UEMs for evaluating Web applications. This allowed us to identify several research gaps, which subsequently provided us with a framework in which new research activities can be more appropriately positioned, and from which useful information for novice usability practitioners can be extracted.     

Cycle elimination for invocation graph-based context-sensitive pointer analysis

Context

Pointer analysis is an important building block of optimizing compilers and program analyzers for C language. Various methods with precision and performance trade-offs have been proposed. Among them, cycle elimination has been successfully used to improve the scalability of context-insensitive pointer analyses without losing any precision.

Objective

In this article, we present a new method on context-sensitive pointer analysis with an effective application of cycle elimination.

Method

To obtain similar benefits of cycle elimination for context-sensitive analysis, we propose a novel constraint-based formulation that uses sets of contexts as annotations. Our method is not based on binary decision diagram (BDD). Instead, we directly use invocation graphs to represent context sets and apply a hash-consing technique to deal with the exponential blow-up of contexts.

Result

Experimental results on C programs ranging from 20,000 to 290,000 lines show that applying cycle elimination to our new formulation results in 4.5 ×speedup over the previous BDD-based approach.

Conclusion

We showed that cycle elimination is an effective method for improving the scalability of context-sensitive pointer analysis.