Stefan Biffl

Software reviews, the state of the practice

A 2002 survey found that many companies use software reviews unsystematically, creating a mismatch between expected outcomes and review implementations. This suggests that many software practitioners understand basic review concepts but often fall to exploit their full potential.

A case study on value-based requirements tracing

Project managers aim at keeping track of interdependencies between various artifacts of the software development lifecycle, to find out potential requirements conflicts, to better understand the impact of change requests, and to fulfill process quality standards, such as CMMI requirements. While there are many methods and techniques on how to technically store requirements traces, the economic issues of dealing with requirements tracing complexity remain open. In practice tracing is typically not an explicit systematic process, but occurs rather ad hoc with considerable hidden tracing-related quality costs. This paper reports a case study on value-based requirements tracing (VBRT) that systematically supports project managers in tailoring requirements tracing precision and effort based on the parameters stakeholder value, requirements risk/volatility, and tracing costs. Main results of the case study were: (a) VBRT took around 35% effort of full requirements tracing; (b) more risky or volatile requirements warranted more detailed tracing because of their higher change probability.

Investigating the defect detection effectiveness and cost benefit of nominal inspection teams

Inspection is an effective but also expensive quality assurance activity to find defects early during software development. The defect detection process, team size, and staff hours invested can have a considerable impact on the defect detection effectiveness and cost-benefit of an inspection. In this paper, we use empirical data and a probabilistic model to estimate this impact for nominal (noncommunicating) inspection teams in an experiment context. Further, the analysis investigates how cutting off the inspection after a certain time frame would influence inspection performance. Main findings of the investigation are: 1) Using combinations of different reading techniques in a team is considerably more effective than using the best single technique only (regardless of the observed level of effort). 2) For optimizing the inspection performance, determining the optimal process mix in a team is more important than adding an inspector (above a certain team size) in our model. 3) A high level of defect detection effectiveness is much more costly to achieve than a moderate level since the average cost for the defects found by the inspector last added to a team increases more than linearly with growing effort investment. The work provides an initial baseline of inspection performance with regard to process diversity and effort in inspection teams. We encourage further studies on the topic of time usage with defect detection techniques and its effect on inspection effectiveness in a variety of inspection contexts to support inspection planning with limited resources.

Integration of heterogeneous engineering environments for the automation systems lifecycle

Production systems will become increasingly complex to handle flexible business processes and systems. Engineering systems and tools from several sources have to cooperate for building agile component-based systems. While there are approaches for the technical integration of component-based industrial automation systems, there is only little work on the effective and efficient integration of engineering tools and systems along the automation systems lifecycle. In this paper we introduce the concept of the “Automation Service Bus” (ASB) based on technical and semantic integration concepts for general software engineering tools and systems. Based on real-world use cases from automation systems engineering we discuss the state of the art, innovation benefits and limitations of the ASB concept, and derive research issues for further work.

PlanningLines: novel glyphs for representing temporal uncertainties and their evaluation

Dealing with temporal uncertainties is a key issue in domains like project management or medical treatment planning. However, support for temporal indeterminacies is not very well integrated in current methods, techniques, and tools. In this paper, we present a visualization technique called PlanningLines that allows for representing temporal uncertainties and aims at supporting project managers in their difficult planning and controlling tasks. We conducted a controlled experiment to gather empirical evidence on the strengths and limitations of our approach. Main results are that PlanningLine users make fewer mistakes and are faster in conducting tasks than users of a traditional visualization technique.

Value-Based Management of Software Testing

Testing is one of the most resource-intensive activities in software development and consumes between 30 and 50% of total development costs according to many studies. Testing is however often not organized to maximize business value and not aligned with a project’s mission. Path, branch, instruction, mutation, scenario, or requirement testing usually treat all aspects of software as equally important, while in practice 80% of the value often comes from 20% of the software. In order to maximize the return of investment gained from software testing, the management of testing needs to maximize its value contribution. In this chapter we motivate the need for value-based testing, describe practices supporting the management of value-based testing, outline a framework for value-based test management, and illustrate the framework with an example.

Software ecosystems vs. natural ecosystems: learning from the ingenious mind of nature

The use of the term ecosystem in the context of extensible software platforms and third-party developers or user communities has made us ponder about the similarities between software ecosystems and natural ecosystems. We therefore compare software ecosystems and natural ecosystems to present an agenda for further research by analyzing some key characteristics of both types of ecosystems. We discuss the regulatory factors and mechanisms existing in nature, and then deduce key challenges that need to be dealt with, in order to achieve healthy operation of software ecosystems.

Business process-based valuation of IT-security

Growing business integration raises the need for secure business processes as security problems can affect the profit and the reputation of a company. However, decisions regarding a reasonable level of security in a business environment are often made in a value-neutral way.This paper presents a framework for the valuation of cost-benefit of various security levels with business processes. The framework can be used for planning security levels in software development and allows further continuous monitoring and improvement of cost-benefit of security measures along with operative business processes.

Semantic Integration of Software and Systems Engineering Environments

Software-intensive systems in business information technology (IT) and industrial automation have become increasingly complex due to the need for more flexible system reconfiguration and business and engineering processes. Systems and software-engineering projects depend on the cooperation of experts from heterogeneous engineering domains using tools that were not designed to cooperate seamlessly. Current semantic-engineering-environment integration is often ad hoc and fragile, thereby making the evolution of tools and the reuse of integration solutions across projects unnecessarily inefficient and risky. This paper describes the engineering-knowledge-base (EKB) framework for engineering-environment integration in multidisciplinary engineering projects. The EKB stores explicit engineering knowledge to support access to and management of engineering models across tools and disciplines by providing 1) data integration based on mappings between local and domain-level engineering concepts; 2) transformations between local engineering concepts; and 3) advanced applications built on these foundations, e.g., end-to-end analyses. As a result, experts from different organizations may use their well-known tools and data models and can access data from other tools in their syntax. The research results have been evaluated in the industrial-application domain of software-intensive production-automation systems. The evaluation results indicate an effort-reduction for reuse in new engineering projects and finding defects earlier in the engineering process.

Increasing the accuracy and reliability of analogy-based cost estimation with extensive project feature dimension weighting

Accurate and reliable software cost estimation is a vital task in software project portfolio decisions like resource scheduling or bidding. A prominent and transparent method of supporting estimators is analogy-based cost estimation, which is based on finding similar projects in historical portfolio data. However, the various project feature dimensions used to determine project analogy represent project aspects differing widely in their relevance; they are known to have varying impact on the analogies - and in turn on the overall estimation accuracy and reliability - , which is not addressed by traditional approaches. This paper (a) proposes an improved analogy-based approach based on extensive dimension weighting, and (ii) empirically evaluates the accuracy and reliability improvements in the context of five real-world portfolio data sets. Main results are accuracy and reliability improvements for all analyzed portfolios and quality measures. Furthermore, the approach indicates a quality barrier for analogy-based estimation approaches using the same basic assumptions and quality measures.