Towards a self-evolving software defect detection process

Software defect detection research typically focuses on individual inspection and testing techniques. However, to be effective in applying defect detection techniques, it is important to recognize when to use inspection techniques and when to use testing techniques. In addition, it is important to know when to deliver a product and use maintenance activities, such as trouble shooting and bug fixing, to address the remaining defects in the software.To be more effective detecting software defects, not only should defect detection techniques be studied and compared, but the entire software defect detection process should be studied to give us a better idea of how it can be conducted, controlled, evaluated and improved.This thesis presents a self-evolving software defect detection process (SEDD) that provides a systematic approach to software defect detection and guides us as to when inspection, testing or maintenance activities are best performed. The approach is self-evolving in that it is continuously improved by assessing the outcome of the defect detection techniques in comparison with historical data.A software architecture and prototype implementation of the approach is also presented along with a case study that was conducted to validate the approach. Initial results of using the self-evolving defect detection approach are promising

Can using Fagan Inspections improve the quality of specification in 2011? A Case Study

In this paper, we explore why Fagan Inspections have become obsolete in the software industry, given the body of evidence which supports their use to improve the quality of software artefacts and the software development process. Since the late 1970’s, much has been written about how Fagan Inspections improve the quality of both processes and outputs of the software development process. The literature indicates that the Fagan Inspection technique can improve quality of software (or other software development artefacts) by a reduction in defects of 60 – 90%. However, recent literature suggests that inspection techniques in general and Fagan Inspections in particular, are no longer used. A study in 1998 found that respondents used inspections either irregularly or not at all. Teams often review artefacts informally, but believe that they are performing an inspection or formal review. The lack of rigour in the review process results in reduced benefits and more defects in the artefacts. To explore this situation, we conducted a case study with a local enterprise and we report on the early findings. These suggest that the introduction of Fagan Inspections may have a number of benefits before they have even been introduced fully, including recognition of flaws in the current development process, development of technical knowledge relating to the software process domain, and improved team relations and a ‘quality’ culture. In addition, the personnel using Fagan Inspection gain experience in the production of ‘quality’ artefacts

Are the perspectives really different? Further experimentation on scenario-based reading of requirements

Perspective-Based Reading (PBR) is a scenario based inspection technique where several reviewers read a document from different perspectives (e.g. user, designer, tester). The reading is made according to a special scenario, specific for each perspective. The basic assumption behind PBR is that the perspectives find different defects and a combination of several perspectives detects more defects compared to the same amount of reading with a single perspective. The paper presents a study which analyses the differences in perspectives. The study is a partial replication of previous studies. It is conducted in an academic environment using graduate students as subjects. Each perspective applies a specific modelling technique: use case modelling for the user perspective, equivalence partitioning for the tester perspective and structured analysis for the design perspective. A total of 30 subjects were divided into 3 groups, giving 10 subjects per perspective. The analysis results show that: (1) there is no significant difference among the three perspectives in terms of defect detection rate and number of defects found per hour, (2) there is no significant difference in the defect coverage of the three perspectives, and (3) a simulation study shows that 30 subjects is enough to detect relatively small perspective differences with the chosen statistical test. The results suggest that a combination of multiple perspectives may not give higher coverage of the defects compared to single-perspective reading, but further studies are needed to increase the understanding of perspective differenc

Exploring the Software Verification and Validation Process with Focus on Efficient Fault Detection

Quality is an aspect of high importance in software development projects. The software organizations have to ensure that the quality of their developed products is what the customers expect. Thus, the organizations have to verify that the product is functioning as expected and validate that the product is what the customers expect. Empirical studies have shown that in many software development projects as much as half of the projected schedule is spent on the verification and validation activities. The research in this thesis focuses on exploring the state of practice of the verification and validation process and investigating methods for achieving efficient fault detection during the software development. The thesis aims at increasing the understanding of the activities conducted to verify and validate the software products, by the means of empirical research in the software engineering domain. A survey of eleven Swedish software development organizations investigates the current state of practice of the verification and validation activities, and how these activities are managed today. The need for communicating and visualising the verification and validation process was expressed during the survey. Therefore the usefulness of process simulations was evaluated in the thesis. The simulations increased the understanding of the relationships between different activities among the involved participants. In addition, an experiment was conducted to compare the performance of the two verification and validation activities, inspection and testing. In the future work, empirical research, including experiment results, will be used for calibration and validation of simulation models, with focus on using simulation as a method for decision support in the verification and validation process

Evaluation of new technologies to support asset management of metro systems

Since 1930, London Underground Limited (LUL) has performed visual inspections to understand the condition of the physical assets such as tunnels, bridges and structures. The major problem with this kind of inspection is the lack in quality of the data, as it depends on the ability of the inspector to assess and interpret the condition of the asset both accurately and with repeatability. In addition, data collection is time-consuming and, therefore, costly when the whole of the metro network needs to be regularly inspected and there are limited periods when access is available. The problems associated with access to the infrastructure have increased significantly with the implementation of the night tube and will increase further as the night tube is extended over the next 5 to 10 years. To determine the condition of metro assets and to predict the need for intervention, monitoring the changes in the assets’ condition is key to any further evaluation and maintenance planning. This thesis presents the outcomes of using new technologies such as Thermography, Kinematic and Static Laser Scanning, Close-Range Photogrammetry and Total Station to measure defects, such as water seepage, mortar loss in joints, lining face loss (in brick tunnels), cracks, corrosion, voids, cavities and spalls. Each technique is explored through three case studies that evaluate the performance and limitation in the determination of the asset condition. The first case study was performed to compare and contrast the use of Euroconsult’s high definition laser survey against a Principal Inspection Report to determine the level of consistency in predicting the asset condition. During this case study, reports from laser surveys and principal inspections of brick tunnels and covered ways were compared. This analysis showed that a direct comparison between the two inspections is not appropriate because the laser inspection does not capture all the defects mentioned in the Engineering Standard S1060. It also showed that to close the gap between the laser survey and visual inspection, laser surveys would have to be performed every year in brick tunnels and then compare any changes in asset condition with that from the previous scan. The second case study was performed using Infrared Thermography (IRT) to identify water seepage in the brick tunnels as well as test the system in a configuration that would allow the survey to be done from an engineering train. A set of calibration tests were performed in the lab and later the technique was trialled on an engineering train. The results showed that it is possible to measure the level of moisture on specific parts of the lining and that the comparison of surveys performed at different times can allow asset managers to react before a seepage is established, potentially reducing the risk of system disruption caused by water ingress in tunnels. The data also revealed that this technique could be used for other purposes, such as examining the condition of other assets such as brackets, cable supports and broken light bulbs. The third case study was performed using a Terrestrial Laser Scanner, Close-Range Photogrammetry and Total Station Survey to identify defects in structures. In order to test these technologies, a wing wall, located on the north-east wing of the HC3 underbridge at Ladbroke Grove Station, was chosen. This case study demonstrated that LUL can easily implement this type of technology to inspect rapidly their buildings and structures, being able to identify defects and monitor their assets for translation, rotation and changes in shape during changes in loading or the decay of the structure (insidious decline) and the construction of nearby assets. In this research, a large volume of data was captured, and further work is needed in order to manage the data using ‘big data’ concepts. Although it may not be possible to fully understand the insidious decline of an asset, the use of these techniques allows us to better understand how a civil asset behaves, potentially reducing the amount of reactive maintenance to a minimum, consequently reducing service costs and falls in revenue due to disruptions in the system. To successfully analyse the data from new technologies a combination of skills is required and different or retrained personal will be needed