WWW.DISSERTATION.XLIBX.INFO
FREE ELECTRONIC LIBRARY - Dissertations, online materials
 
<< HOME
CONTACTS



Pages:     | 1 |   ...   | 14 | 15 || 17 | 18 |   ...   | 27 |

«Software Fault Reporting Processes in Business-Critical Systems Jon Arvid Børretzen Doctoral Thesis Submitted for the partial fulfilment of the ...»

-- [ Page 16 ] --
In this paper, we describe our experience with using problem reports from industry for quality assessment. The non-uniform terminology used in problem reports and validity concerns have been subject of earlier research but are far from settled. To distinguish between terms such as defects or errors, we propose to answer three questions on the scope of a study related to what (problem appearance or its cause), where (problems related to software; executable or not; or system), and when (problems recorded in all development life cycles or some of them). Challenges in defining research questions and metrics, collecting and analyzing data, generalizing the results and reporting them are discussed. Ambiguity in defining problem report fields and missing, inconsistent or wrong data threatens the value of collected evidence. Some of these concerns could be settled by answering some basic questions related to the problem reporting fields and improving data collection routines and tools.

Categories and Subject Descriptors D.2.8 [Software Engineering]: Metrics- product metrics, process metrics; D.2.4 [Software Engineering]: Software/Program Verification- reliability, validation.

General Terms Measurement, Reliability.

Keywords Quality, defect density, validity.

1. INTRODUCTION

Data collected on defect or faults (or in general problems) are used in evaluating software quality in several empirical studies. For example, our review of extant literature on industrial software reuse experiments and case studies verified that problem-related measures were used in 70% of the reviewed papers to compare quality of reused software components versus the non-reused ones, or development with systematic reuse to development without it. However, the studies report several concerns using data from problem reports and we identified some common concerns as well. The purpose of this paper is to reflect over these concerns and generalize the experience, get feedback from other researchers on the problems in using problem reports, and how they are handled or should be handled.

In this paper, we use data from 6 large commercial systems all developed by the Norwegian industry. Although most quantitative results of the studies are already published [4, 12, 18], we felt that there is a need for summarizing the experience in using problem reports, identifying common questions and concerns, and raising the level of discussion by answering them. Examples from similar research are provided to further illustrate the points. The main goal is to improve the quality of future research on product or process quality using problem reports.

The remainder of this paper is organized as follows. Section 2 partly builds on work of others; e.g., [14] has integrated IEEE standards with the Software Engineering Institute (SEI)’s framework and knowledge from four industrial companies to build an entityrelationship model of problem report concepts, and [9] has compared some attributes of a number of problem classification schemes (the Orthogonal Defect ClassificationODC [5], the IEEE Standard Classification for Software Anomalies (IEEE Std. 1044and a classification used by Hewlett-Packard). We have identified three dimensions that may be used to clarify the vagueness in defining and applying terms such as problem, anomaly, failure, fault or defect. In Section 3 we discuss why analyzing data from problem reports is interesting for quality assessment and who the users of such data are. Section 4 discusses practical problems in defining goals and metrics, collecting and analyzing data, and reporting the results through some examples.

Finally, Section 5 contains discussion and conclusion.

2. TERMINOLOGY

There is great diversity in the literature on the terminology used to report software or system related problems. The possible differences between problems, troubles, bugs, anomalies, defects, errors, faults or failures are discussed in books (e.g., [7]), standards and classification schemes such as IEEE Std. 1044-1993, IEEE Std. 982.1-1988 and 982.2-1988 [13], the United Kingdom Software Metrics Association (UKSMA)’s scheme [24] and the SEI’s scheme [8], and papers; e.g., [2, 9, 14]. The intention of this section is not to provide a comparison and draw conclusions, but to classify differences and discuss the practical impacts for research. We have identified the following three questions that should be answered to distinguish the above terms from one another, and

call these as problem dimensions:

What- appearance or cause: The terms may be used for manifestation of a problem (e.g., to users or testers), its actual cause or the human encounter with software. While there is consensus on “failure” as the manifestation of a problem and “fault” as its cause, other terms are used interchangeably. For example, “error” is sometimes used for the execution of a passive fault, and sometimes for the human encounter with software [2]. Fenton uses “defect” collectively for faults and failures [7], while Kajko-Mattson defines “defect” as a particular class of cause that is related to software [14].

Where- Software (executable or not) or system: The reported problem may be related to software or the whole system including system configuration, hardware or network problems, tools, misuse of system etc. Some definitions exclude non-software related problems while others include them. For example, the UKSMA’s defect classification scheme is designed for software-related problems, while SEI uses two terms: “defects” are related to the software under execution or examination, while “problems” may be caused by misunderstanding, misuse, hardware problems or a number of other factors that are not related to software. Software related problems may also be recorded for executable software or all types of artefacts: “Fault” is often used for an incorrect step, logic or data definition in a computer program (IEEE STd. 982.1-1998), while a “defect” or “anomaly” [13] may also be related to documentation, requirement specifications, test cases etc. In [14], problems are divided into static and dynamic ones (failures), where the dynamic ones are related to executable software.





When- detection phase: Sometimes problems are recorded in all life cycle phases, while in other cases they are recorded in later phases such as in system testing or later in field use. Fenton gives examples of when “defect” is used to refer to faults prior to coding [7], while according to IEEE STd. 982.1-1998, a “defect” may be found during early life cycle phases or in software mature for testing and operation [from 14]. SEI distinguishes the static finding mode which does not involve executing the software (e.g., reviews and inspections) from the dynamic one.

Until there is agreement on the terminology used in reporting problems, we must be aware of these differences and answer the above questions when using a term.

Some problem reporting systems cover enhancements in addition to corrective changes.

For example, an “anomaly” in IEEE Std. 1044-1993 may be a problem or an enhancement request, and the same is true for a “bug” as defined by OSS (Open Source Software) bug reporting tools such as Bugzilla [3] or Trac [23]. An example of ambiguity in separating change categories is given by Ostrand et al. in their study of 17 releases of an AT&T system [20]. In this case, there was generally no identification in the database of whether a change was initiated because of a fault, an enhancement, or some other reason such as a change in the specifications. The researches defined a rule of thumb that if only one or two files were changed by a modification request, then it was likely a fault, while if more than two files were affected, it was likely not a fault.

We have seen examples where minor enhancements were registered as problems to accelerate their implementation and major problems were classified as enhancement requests (S5 and S6 in Section 4).

In addition to the diversity in definitions of a problem, problem report fields such as Severity or Priority are also defined in multiple ways as discussed in Section 4.

3. QUALITY VIEWS AND DEFECT DATA

In this section, we use the term “problem report” to cover all recorded problems related to software or other parts of a system offering a service, executable or non-executable artefacts, and detected in phases specified by an organization, and a “defect” for the cause of a problem.

Kitchenham and Pfleeger refer to David Garvin’s study on quality in different application domains [15]. It shows that quality is a complex and multifaceted concept that can be described from five perspectives: The user view (quality as fitness for

–  –  –

Figure 1. Quality views associated to defect data, and relations between them Q1.

Evaluating product quality from a user’s view. What truly represents software quality in the user’s view can be elusive. Nevertheless, the number and frequency of defects associated with a product (especially those reported during use) are inversely proportional to the quality of the product [8], or more specific to its reliability. Some problems are also more severe from the user’s point of view.

Q2.Evaluating product quality from the organization’s (developers’) view. Product quality can be studied from the organization’s view by assuming that improved internal quality indicators such as defect density will result in improved external behavior or quality in use [15]. One example is the ISO 9126 definition of internal, external and quality-in-use metrics. Problem reports may be used to identify defectprone parts and take actions to correct them and prevent similar defects.

Q3.Evaluating software process quality. Problem reports may be used to identify when most defects are injected, e.g., in requirement analysis or coding. Efficiency of Verification and Validation (V&V) activities in identifying defects and the organization’s efficiency in removing such defects are also measurable by defining proper metrics of defect data [5].

Q4.Planning resources. Unsolved problems represent work to be done. Cost of rework is related to the efficiency of the organization to detect and solve defects and to the maintainability of software. A problem database may be used to evaluate whether the product is ready for roll-out, to follow project progress and to assign resources for maintenance and evolution.

Q5.Value-based decision support. There should be a trade-off between the cost of repairing a defect and its presumed customer value. Number of problems and criticality of them for users may also be used as a quality indicator for purchased or reused software.

–  –  –

We conclude that the contents of problem reports should be adjusted to quality views.

We discuss the problems we faced in our use of problem reports in the next section.

4. INDUSTRIAL CASES Ours and other’s experience from using problem reports in assessment, control or prediction of software quality (the three quality functions defined in [21]) shows problems in defining measurement goals and metrics, collecting data from problem reporting systems, analyzing data and finally reporting the results. An overview of our case studies is shown in Table 2.

4.1 Research Questions and Metrics

The most common purpose of a problem reporting system is to record problems and follow their status (maps to Q1, Q4 and Q5). However, as discussed in Section 3, they may be used for other views as well if proper data is collected. Sometimes quality views and measurement goals are defined top-down when initiating a measurement program (e.g., by using the Goal-Question-Metric paradigm [1]), while in most cases the topdown approach is followed by a bottom-up approach such as data-mining or Attribute Focusing (AF) to identify useful metrics when some data is available; e.g., [17, 19, 22].

We do not intend to focus on the goals more than what is already discussed in Section 3 and refer to literature on that. But we have encountered the same problem in several industrial cases which is the difficulty of collecting data across several tools to answer a single question. Our experience suggests that questions that need measures from different tools are difficult to answer unless effort is spent to integrate the tools or data.

Examples are:

− In S6, problems for systems not based on the reusable framework were not recorded in the same way as those based on it. Therefore it was not possible to evaluate whether defect density is improved or not by introducing a reusable framework [12].

− In S5, correction effort was recorded in an effort reporting tool and modified modules could be identified by analyzing change logs in the configuration management tool, without much interoperability between these tools and the problem reporting tool. This is observed in several studies. Although problem reporting systems often included fields for reporting correction effort and modifications, these data were not reliable or consistent with other data. Thus evaluating correction effort or the number of modified modules per defect or type of defect was not possible.

Graves gives another example on the difficulty of integrating data [11]. The difference between two organizations’ problem reporting systems within the same company lead to a large discrepancy in the fault rates of modules developed by the two organizations because the international organization would report an average of four faults for a problem that would prompt one fault for the domestic organization.

To solve the problem, researchers often collect or mine industrial data, transform it and save it in a common database for further analysis. Examples are given in the next section.

–  –  –

4.2 Collecting and Analyzing Data

Four problems are discussed in this section:

1. Ambiguity in defining problem report fields even when the discussion on

terminology is settled. A good example is the impact of a problem:

− The impact of a problem on the reporter (user, customer, tester etc.) is called for Severity in [24], Criticality in [8] or even Product status in IEEE Std. 1044This field should be set when reporting a problem.



Pages:     | 1 |   ...   | 14 | 15 || 17 | 18 |   ...   | 27 |


Similar works:

«The Economics of Housing Finance Reform: Privatizing, Regulating and Backstopping Mortgage Markets* David Scharfstein Harvard Business School and NBER Adi Sunderam Harvard University February 2011 ABSTRACT This paper analyzes the two leading types of proposals for reform of the housing finance system: (i) broad-based, explicit, priced government guarantees of mortgage-backed securities (MBS) and (ii) privatization. Both proposals have drawbacks. Properly-priced guarantees would have little...»

«The European Qualifications Framework and the European Lifelong Learning Perspective: How European countries are preparing to cope with the new philosophy of VET Thomas Deissinger, University of Konstanz Abstract The paper picks up “matching problems” related to current European education policy moves by referring to the German, the French and the Austrian VET system respectively. As we here refer to “dual systems” or “school-based systems” respectively, the pre-conditions for...»

«Globalization and the Provision of Incentives inside the Firm: The Effect of Foreign Competition Vicente Cunat, ˜ London School of Economics Maria Guadalupe, Columbia University and CEPR This article studies the effect of changes in foreign competition on the structure of compensation and incentives of U.S. executives. We find that import penetration (instrumented with exchange rates and tariffs) leads to more incentive provision in a variety of ways. First, it increases the sensitivity of...»

«5 Websites Where You Can Make Money Right Now A Quick Guide to Making More Money by: Brian Lang (Small Business Ideas Blog) www.smallbusinessideasblog.com 5 Websites Where You Can Make Money Right Now 5 Websites Where You Can Make Money Right Now – Disclaimer and Legal Stuff This report is for informational purposes only. Note that any stories or earnings in this publication are based on personal experiences and should not be viewed as typical or guaranteed. Although every effort was made to...»

«Minutes of 2016 Second Meeting ARRL Board of Directors July 15-16, 2016 Summary Agenda 1. Roll call 2. Moment of silence 3. Courtesies 4. Consideration of the agenda of the meeting 5. Receipt and consideration of financial reports 6. Motion to adopt Consent Agenda 7. Consideration of items removed from Consent Agenda 8. Consider recommendations of the standing committees 9. Consider additional recommendations as contained in reports 10. Directors’ motions 11. Any other business 12....»

«July 15, 2015 www.citizen.org Financial Services Conflict of Interest Act Outlining the need for increased revolving-door and reverse revolving-door legislation Acknowledgments This report was written by Craig Holman, Ph.D., government affairs lobbyist, and Emma Stein, researcher, Public Citizen’s Congress Watch division, and edited by Lisa Gilbert, director, Public Citizen’s Congress Watch division. About Public Citizen Public Citizen is a national non-profit organization with more than...»

«' MINUTES SENATE FINANCE COMMITTEE August 14, 1986 1:30 3:00 300 Morrill Hall Participants: Carl Adams, John Adams, David Hamilto~, Paige Johnson, Wendell Johnson, Vice President Stanley Kegler, Gerald Klement, Acting Vice President V. Rama Murthy, W. Phillips Shively (chair). Visitors: Fred Lukermann, Jud Sheridan, Eldred Smith, Maureen Smith, and several others.1. The minutes of the July 22 meeting were approved with one correction: on page 3, the first sentence in the Consensus paragraph...»

«Measuring a Brand’s Value A Qualitative study of Media Groups Bachelor Thesis School of Business, Economics and Law University of Gothenburg Spring 2014 Tutor: Markus Rudin Authors: Ellen Svanberg Julia Maxén Acknowledgements This thesis has been written under the support of Markus Rudin at Financial Accounting, School of Business, Economics and Law, Gothenburg. Markus has guided us throughout the work process with professional support and rewarding reflections which we are thankful for. We...»

«Liquidity Management and Corporate Investment During a Financial Crisis* Murillo Campello Erasmo Giambona University of Illinois University of Amsterdam & NBER campello@illinois.edu e.giambona@uva.nl John R. Graham Campbell R. Harvey Duke University Duke University & NBER & NBER john.graham@duke.edu cam.harvey@duke.edu This Draft: October 12, 2010 Key words: Financial crisis, liquidity management, investment spending, credit lines, drawdown activity, cash savings. JEL classification: G31, G32....»

«Leading the Class From Ph.D. Graduate to Tenured Faculty Doctoral Scholars June 2015 Program BUSINESS AND MANAGEMENT l VANESSA BRANTLEY l DEACUE FIELDS l VENESSA FUNCHES l KRISTENA GAYLOR l JILL HOUGH l CHRISTOPHER JOHNSON l KIMBERLY JOHNSON l SHAWN LONG l ROCHELLE PARKS-YANCY l CYNTHIA TAYLOR l EDUCATION l DENISE NATASHA BREWLEY l JOE LOTT l SELINA MIRELES l LURIA STUBBLEFIELD l ENGINEERING l EDWARD BROWN l ARSENIO CACERES l HUDSON JACKSON l WILBUR WALTERS l HEALTH PROFESSIONS l EDWARD BELL l...»

«Erasmus University Rotterdam Department of Business Economics Section: Finance Bachelor Thesis A Model of Bankruptcy Prediction: Calibration of Atman’s Z-score for Japan Supervisor: Author: Dr. Nico van der Sar Traian Gur˘u a 340938 Abstract Early warning of financial distress is vital for bankruptcy prediction and the study of bankruptcy risk became of main interest for the various stakeholders of the financially distressed firms. This paper is a follow up of Altman (1968) Z-score, and...»

«Sanjiv Das Santa Clara University Sanjiv Das is Professor of Finance at Santa Clara University's Leavey School of Business, and previously held faculty appointments as Associate Professor at Harvard Business School and UC Berkeley. He holds post-graduate degrees in Finance (M.Phil and Ph.D. from New York University), Computer Science (M.S. from UC Berkeley), an MBA from the Indian Institute of Management, Ahmedabad, and he did undergraduate work in Accounting and Economics (University of...»





 
<<  HOME   |    CONTACTS
2016 www.dissertation.xlibx.info - Dissertations, online materials

Materials of this site are available for review, all rights belong to their respective owners.
If you do not agree with the fact that your material is placed on this site, please, email us, we will within 1-2 business days delete him.