Survey on Safety Evidence Change Impact Analysis in Practice: Detailed Description and Analysis

Critical systems must comply with safety standards in many application domains. This involves gathering safety evidence in the form of artefacts such as safety analyses, system specifications, and testing results. These artefacts can evolve during a system’s lifecycle, and impact analysis might be necessary to guarantee that system safety and compliance are not jeopardised. Although extensive research has been conducted on impact analysis and on safety evidence management, the knowledge about how safety evidence change impact analysis is addressed in practice is limited. This technical report presents a survey targeted at filling this gap by analysing the circumstances under which safety evidence change impact analysis is addressed, the tool support used, and the challenges faced. We obtained 97 valid responses representing 16 application domains, 28 countries, and 47 safety standards. The results suggest that most projects deal with safety evidence change impact analysis during system development and mainly from system specifications, the level of automation in the process is low, and insufficient tool support is the most frequent challenge. Other notable findings are that safety case evolution should probably be better managed, no commercial impact analysis tool has been reported as used for all artefact types, and experience and automation do not seem to greatly help in avoiding challenges

Investigating and Managing Design Margins throughout the Product Development Process

The automotive industry, like other sectors, faces a number of technological challenges in terms of meeting different legislations and developing products highly customised with a short lead time. They also have to manage the trade-offs between the price for the customer and the overall cost of the product development. This thesis argues that design margins are a decisive factor with regard to many trade-offs that engineers may wish to make. These margins represent room for manoeuvre in the developing design. On the other hand, design margins allow engineers to accommodate new requirements without leading to costly engineering changes. If a change becomes necessary, the engineers might modify parameters where there are still margins with respect to the new requirements. Therefore engineers can avoid major redesigns to their existing components and systems. Ultimately this has the potential to enable control of the resulting development time and cost. While margins are an intuitive concept, no clear and consistent definitions exist. The concept is relatively under-investigated area of design research. A comprehensive literature review and an empirical study at Volvo Global Truck Technology, emphasised the main issues and showed that there is a strong industrial need for support with margins, especially to understand how margins shape the design process. The concept of design margins, consisting of buffer and excess is developed. The key to managing product development is the transition from buffer to excess throughout the design process. This gives designers and engineers a rich way to express and communicate information about the forthcoming design to other team members, other teams and suppliers. The thesis proposes a conceptual framework to investigate and capture design margins. The overall model indicates that a clear elicitation and an explicit documentation of design margins can help decision makers implement more efficiently the necessary changes involved in product development: design margins are seen as a critical aspect of product design and developmen

Proposition and evaluation of a software Change Impact Analysis model

International audienc

A review of software change impact analysis

Change impact analysis is required for constantly evolving systems to support the comprehension, implementation, and evaluation of changes. A lot of research effort has been spent on this subject over the last twenty years, and many approaches were published likewise. However, there has not been an extensive attempt made to summarize and review published approaches as a base for further research in the area. Therefore, we present the results of a comprehensive investigation of software change impact analysis, which is based on a literature review and a taxonomy for impact analysis. The contribution of this review is threefold. First, approaches proposed for impact analysis are explained regarding their motivation and methodology. They are further classified according to the criteria of the taxonomy to enable the comparison and evaluation of approaches proposed in literature. We perform an evaluation of our taxonomy regarding the coverage of its classification criteria in studied literature, which is the second contribution. Last, we address and discuss yet unsolved problems, research areas, and challenges of impact analysis, which were discovered by our review to illustrate possible directions for further research

Using requirements and design information to predict volatility in software development

We hypothesise that data about the requirements and design stages of a software development project can be used to make predictions about the subsequent number of development changes that software components will experience. This would allow managers to concentrate time-consuming efforts (such as traceability and staff training) to a few at-risk, cost-effective areas, and may also allow predictions to be made at an earlier stage than is possible using traditional metrics, such as lines of code. Previous researchers have studied links between change-proneness and metrics such as measures of inheritance, size and code coupling. We extend these studies by including measures of requirements and design activity as well. Firstly we develop structures to model the requirements and design processes, and then propose some new metrics based on these models. The structures are populated using data from a case study project and analysed alongside existing complexity metrics to ascertain whether change-proneness can be predicted. Finally we examine whether combining these metrics with existing metrics improves our ability to make predictions about change-proneness. First results show that our metrics can be linked to the quantity of change experienced by components in a software development project (potentially allowing predictions to take place earlier than before) but that best results are obtained by combining existing complexity metrics such as size, or combining existing metrics with our newer metrics.EThOS - Electronic Theses Online ServiceBAE Systems : Engineering and Physical Sciences Research CouncilGBUnited Kingdo