Peter Wallin

What Does Research Say about Agile and Architecture

Agile has been used to refer to a software development paradigm that emphasizes rapid and flexible development. In the meanwhile, we have through our practical experiences in scaling up agile methods, noticed that architecture plays an important role. Due to the inter-relationship between agile methods and architecture, as well as divergent perceptions on their correlation stated in numerous sources, we are motivated to find out how these perceptions are supported by findings in the research community in general and in empirical studies in particular. To fully benefit from agile practices and architectural disciplines, we need empirical data on the perceived and experienced impacts of introducing agile methods to existing software development process, as well as correlations between agile and architecture. In this paper, we survey the research literature for statements made regarding the relationship between agile development and software architecture. The main findings are that there is a lack of scientific support for many of the claims that are concerned with agile and architecture, and more empirical studies are needed to fully reveal the benefits and drawbacks implied by an agile software development method.

A Case Study of Issues Related to Automotive E/E System Architecture Development

The use of electronics in vehicles is increasing quickly and the systems are becoming increasingly complex. This makes the engineering of these advanced computer-based systems more and more difficult. In particular, finding a good architecture is a prerequisite for successful design. In this study we investigate key issues related to real-world decisions regarding a cars electrical and electronic system architecture. To extract the key issues an exploratory case study was performed at a car manufacturer. We used semi- formal interviews complemented with a survey to validate the results. The contribution of this paper is twelve issues that reflect the situation at a car manufacturer. Also, possible actions to deal with these issues are provided.

Making Decisions in Integration of Automotive Software and Electronics: A Method Based on ATAM and AHP

In this paper we present a new method for making decisions on integration strategy for in-vehicle automotive systems. We describe the problem of choosing integration strategy and we describe the method, which is a combination of the Architecture Tradeoff Analysis Method, ATAM, and the Analytical Hierarchy Process, AHP. We exemplify the use of the proposed method by evaluating the integration decisions concerning the physical connection of a realistic example system; a computer controlled automatic gearbox. We present analysis on the use of the method and conclude that the method has several benefits compared to ATAM or AHP used individually. The method firstly supports a structured way of listing system goals, and secondly, it also supports the making of design decisions.

Assessing the influence on processes when evolving the software architecture

Software intensive products and systems evolve over the life-cycle. Changing business objectives may drive architectural or process changes. Altering either architecture or process might influence the other. Also the organization may influence and be influenced. This paper describes these relationships and proposes a method for assessing the influence on process that a proposed architectural change can have. The method includes the use of scenarios and process reference models. A case study where the method has been used is described, identifying the need for changes in the processes to be able to utilize the advantages made possible due to the architectural evolution. The case study supports our proposal that a structured method to assess the impacts on process when changing the architecture of a system helps to reduce risks and to facilitate the envisioned business benefits. This also identifies the need to devise methods for other types of changes, e.g. how a process change may influence architecture or organization.

Issues Related to Development of E/E Product Line Architectures in Heavy Vehicles

The amount of electronics in vehicles is growing quickly, thus systems are becoming increasingly complex which makes the engineering of these software intensive systems more and more difficult. In the automotive industry the use of product line architectures enables a set of vehicles to share architecture to decrease cost and increase quality. In this study we investigate key issues related to realworld decisions regarding electrical and electronic product line architecture for heavy vehicles. To extract key issues a multiple exploratory case study at two heavy vehicle manufacturers was performed. We used semi-formal interviews complemented with a survey to validate the results. The contribution of this study is 14 issues that reflect the situation at the two companies. Many of the identified issues relate to non technical areas such as organization, process, methods and tools, and management. Moreover, possible actions to deal with these issues are discussed.

Architecture knowledge management during system evolution: observations from practitioners

It is widely accepted that awareness of architectural decisions enables better management and planning of system evolution, refactoring, and modernization efforts. In this paper we report data from interviews with software architects about how practitioners utilize architecture during system evolution. Our results show, despite the widely shared view that long-lived systems are better off with strong architectures; basic architecture-centric practices are not followed systematically. The key gap we observe is in correct and timely communication of architectural issues. This overall finding is not surprising. However, our data also contributes to how architecture knowledge management activities can be focused for most benefit throughout a systems lifespan. While the often-referenced problem is lack of time spent on documentation and design practices, our interviews show that lack of quality attribute reasoning early on, and during the lifespan of the system is a key contributor to failing to use architecture knowledge effectively during evolution.

Problems and their mitigation in system and software architecting

Context: Today, software and embedded systems act as enablers for developing new functionality in traditional industries such as the automotive, process automation, and manufacturing automation domains. This differs from 25-30years ago when these systems where based on electronics and electro-mechanical solutions. The architecture of the embedded system and of the software is important to ensure the qualities of these applications. However, the effort of designing and evolving the architecture is in practice often neglected during system development, whilst development efforts are centered on implementing new functionality. Objective: We present problems and success factors that are central to the architectural development of software intensive systems in the domain of automotive and automation products as judged by practitioners. Method: The method consisted of three steps. First, we used semi-structured interviews to collect data in an exploratory manner. As a second step, a survey based on problems extracted from the interview data was used to investigate the occurrence of these problems at a wider range of organizations. In order to identify and suggest how to mitigate the problems that were considered important, we finally performed root cause analysis workshops, and from these a number of success factors were elicited. Results: A total of 21 problems have been identified based on the interview data, and these are related to the technical, organizational, project, and agreement processes. Based on the survey results, the following four problems were selected for a root cause analysis: (1) there is a lack of process for architecture development, (2) there is a lack of method or model to evaluate the business value when choosing the architecture, (3) there is a lack of clear long-term architectural strategy, and (4) processes and methods are less valued than knowledge and competence of individuals. Conclusion: In conclusion, the following identified success factors are crucial components to be successful in developing software intensive systems: (1) define an architectural strategy, (2) implement a process for architectural work, (3) ensure authority for architects, (4) clarify the business impact of the architecture, and (5) optimize on the project portfolio level instead of optimizing each project.

Automated model translations for vehicular real-time embedded systems with preserved semantics

Model-based development of software architecture for real-time embedded systems in modern vehicles has had a surge in the last few years. While the introduction of models into the development of real-time embedded systems has increased efficiency in some parts of the engineering process, the models are also cause of novel concerns. In particular, mismatch between structural and semantic assumptions in modeling languages used in different parts of the design process of such systems cause large problems when design artifacts are transformed between modeling languages.

Analysis of the information needs of an autonomous hauler in a quarry site

Autonomous and intelligent construction equipment is an emergent area of research, which shares many characteristics with on-road autonomous vehicles, but also have fundamental differences. Construction vehicles usually perform repetitive tasks in confined sites, such as quarries, and cooperate with other vehicles to complete common missions. A quarry can be viewed as a system-of-systems and the vehicles are individual systems within the site system. Therefore it is important to analyze the site system, i.e. included vehicles, surrounding systems, and system context, before the introduction of autonomous vehicles. It is necessary to map the needed infrastructure, and the needed input information from on-board sensors and off-board information suppliers, before designing the vehicle electronics system. This paper describes how we identified sensory and input signal needs for an autonomous articulated hauler in a scenario at a quarry site. Different architectural alternatives are evaluated and a set-up for a quarry site is suggested.

Energy savings by wireless control of speed, scheduling and travel times for hauling operation

A Quarry and Aggregate production site consist of sequential production processes and activities to process and produce the output products. Compared to a fixed manufacturing plant, the quarry processes involve mobile machines such as wheel loaders, trucks and articulated haulers and a highly dynamic road infrastructure. Today, the mobile machines are generally not synchronized or controlled towards the overall throughput of the site in real time. This indicates a general improvement potential in increased productivity at quarry sites, but also unsolved challenges for the same reason. Assuming a wireless control system that controls speed and throughput of the different processes and activities, there would be a fuel reduction potential in controlling the mobile machines. This optimization requires models of machine fuel consumption for different applications, velocities and travel times. The main contribution of this paper is the presentation of fuel measurements based on different speeds, site application characteristics and travel times for hauling operation. The fuel measures reveal important aspects regarding how different velocities impact fuel consumption. The results of fuel measurements show a potential in fuel savings of up to 42% and a typical improvement of 20-30% depending on machine speeds, travel times, application and site characteristics. Based on this, some of the applications and challenges in wirelessly controlling machines are discussed.