| 1. |
- Gustavsson, Håkan, 1977-
(författare)
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Lean Thinking Applied to System Architecting
- 2011
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Software intensive systems are an increasing part of new products, which make the business impact significant. This is especially true for the automotive industry where a very large part of new innovations are realized through the use of software. The architecture of the software intensive system will enable value creation when working properly or, in the worst case, prevent value creation. Lean thinking is about focusing on the increase of customer value and on the people who add value. This thesis investigates how system architecting is performed in industry and how it can be improved by the use of Lean thinking. The architecting process does not create immediate value to the end customer, but rather create the architecture on which value in terms of product features and functionality can be developed. A Lean tool used to improve the value creation within a process is Value Stream Mapping (VSM). We present a method based on VSM which is adapted to enable analysis of the architecting process in order to identify improvements. A study of architecting at two companies shows what effect differences such as a strong line organization or a strong project organization has on the architecting process. It also shows what consequence technical choices and business strategy have on the architecting process. In order to improve the understanding of how architecting is performed a study including architects at six different internationally well-known companies have been interviewed. The study presents the practices that are found most successful. The context of the different companies as well as the architecting practices are compared and analyzed. The early design decisions made when developing software-intensive systems are crucial to the outcome of development projects. In order to improve the decision making process a method was developed based on Real Options. The method improves the customer focus of critical design decision by taking the value of flexibility into account. This thesis provides a toolbox of knowledge on how Lean thinking can be applied to system architecting and also presents how architecting is performed in industry today.
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| 2. |
- Mohan, Naveen
(författare)
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Architecting Safe Automated Driving with Legacy Platforms
- 2018
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Modern vehicles have electrical architectures whose complexity grows year after year due to feature growth corresponding to customer expectations. The latest of the expectations, automation of the dynamic driving task however, is poised to bring about some of the largest changes seen so far. In one fell swoop, not only does required functionality for automated driving drastically increase the system complexity, it also removes the fall-back of the human driver who is usually relied upon to handle unanticipated failures after the fact. The need to architect thus requires a greater rigour than ever before, to maintain the level of safety that has been associated with the automotive industry.The work that is part of this thesis has been conducted, in close collaboration with our industrial partner Scania CV AB, within the Vinnova FFI funded project ARCHER. This thesis aims to provide a methodology for architecting during the concept phase of development, using industrial practices and principles including those from safety standards such as ISO 26262. The main contributions of the thesis are in two areas. The first area i.e. Part A contributes, (i) an analysis of the challenges of architecting automated driving, and serves as a motivation for the approach taken in the rest of this thesis, i.e. Part B where the contributions include, (ii) a definition of a viewpoint for functional safety according to the definitions of ISO 42010, (iii) a method to systematically extract information from legacy components and (iv) a process to use legacy information and architect in the presence of uncertainty to provide a work product, the Preliminary Architectural Assumptions (PAA), as required by ISO 26262. The contributions of Part B together comprise a methodology to architect the PAA. A significant challenge in working with the industry is finding the right fit between idealized principles and practical utility. The methodology in Part B has been judged fit for purpose by different parts of the organization at Scania and multiple case studies have been conducted to assess its usefulness in collaboration with senior architects. The methodology was found to be conducive in both, generating the PAA of a quality that was deemed suitable to the organization and, to find inadequacies in the architecture that had not been found earlier using the previous non-systematic methods. The benefits have led to a commissioning of a prototype tool to support the methodology that has begun to be used in projects related to automation at Scania. The methodology will be refined as the projects progress towards completion using the experiences gained.A further impact of the work is seen in two patent filings that have originated from work on the case studies in Part B. Emanating from needs discovered during the application of the methods, these filed patents (with no prior publications) outline the future directions of research into reference architectures augmented with safety policies, that are safe in the presence of detectable faults and failures. To aid verification of these ideas, work has begun on identifying critical scenarios and their elements in automated driving, and a flexible simulation platform is being designed and developed at KTH to test the chosen critical scenarios.
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| 3. |
- Wallin, Peter, 1979-
(författare)
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Identifying and Managing Key Challenges in Architecting Software-Intensive Systems
- 2011
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In many traditional industry applications, such as automotive, process automation and manufacturing automation, software plays a crucial role as an enabler for the introduction of new functionality and retaining competitiveness. The system and software architecture plays an important part in ensuring the systems’ qualities. However, the design of the architecture may be neglected during system development, whilst development efforts are centered on implementing new functionality. The architecture is supposed to support and enable key quality attributes such as safety, reliability, maintainability and flexibility, and so on. This thesis identifies some of the key issues in architecting these software intensive systems. In total, 21 issues have been identified; examples of these issues are (1) there is a lack of process for architecture development, (2) there is a lack of method or model to evaluate business value when choosing architecture, (3) there is a lack of clear long-term architectural strategy, and (4) processes and methods are less valued than individuals’ knowledge and competence. Through a series of workshops, root causes were identified for a selection of these issues. Based on these root causes, five success factors were identified. The success factors are (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. In an attempt to provide a possible solution to some of the issues, a method has been created to evaluate how new functionality is successfully integrated into an existing architecture. The method is a combination of the Architecture Tradeoff Analysis Method, ATAM, and the Analytical Hierarchy Process, AHP. The method firstly supports a structured way of listing system goals, and secondly, it also supports design decision-making. Since several issues relate to the organization and are affected by management, a comparison was made between the view of management and architects. This study revealed that one cause for the lack of focus on architecture could be that the existing performance measurement systems used by management all focus on the later phases of development when the architecture is already set.
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| 4. |
- Wallin, Peter, 1979-
(författare)
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Key Challenges in Decision Making for Automotive E/E Architectures
- 2008
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The amount of electronics in vehicles is growing quickly, thus systems are becoming increasingly complex making the engineering of these software intensive systems more and more difficult. In particular, an architecture supporting the business goals is a prerequisite for successful design.In this thesis two case studies have been made including three automotive companies with purpose to investigate the key issues related to real-world decisions when developing Electrical and Electronic (E/E) system architectures in the automotive industry.The results show that many of the identified issues relate to non technical areas such as organization, process, methods and tools, and management. Examples of identified issues are the deficient understanding of the electrical system and software at management level, and the lack of a specific process for architecture development. To cope with these issues we suggest the following actions: Educate management, increase the use of structured decision making, improve the architecture development process, clarify responsibilities in the organization and clarify development strategies.As a possible solution to one of the suggested actions we have developed a method to evaluate how new functionality is successfully integrated into an existing architecture. Themethod is a combination of the Architecture Tradeoff Analysis Method, ATAM, and the Analytical Hierarchy Process, AHP. The method firstly supports a structured way of listing system goals, and secondly, it also supports the making of design decisions.
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| 5. |
- Asplund, Fredrik, 1977-
(författare)
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Tool Integration and Safety : A Foundation for Analysing the Impact of Tool Integrationon Non-functional Properties
- 2012
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The increasing complexity of embedded systems development is becoming difficult to handle with development environments based on disjoint engineering tools. Support for interactions between various engineering tools, especially through automated means, has therefore received an increased amount of attention during the last few years. The subsequent increase in the amount of tool integration is leading to an increased impact of tool integration on non-functional properties of development efforts, development environments and end products. At the same time there is a lack of methods and tools for analysing the relationship between these properties and tool integration. To establish a foundation for analysing this generic relationship, the specific relationship between tool integration and the safety of end products is analysed in this thesis.A survey was conducted to analyze the State of the Art of tool integration as related to safety. This survey specifically identified the lack of an efficient handling of tool integration by modern safety standards as an important concern. In relation to this survey, three theories were identified as of specific importance. These are the school of thought known as Systems Thinking, the Systems-Theoretic Accident Model and Processes (STAMP) causality model and the System-Theoretic Process Analysis (STPA) hazard analysis technique.Building on these theories, this thesis provides original contributions intended to (1) describe concepts and models related to tool integration and safety (the first and second contribution), (2) link tool integration to safety in a way that reduces complexity during analysis (the third contribution) and (3) propose how to interpret and make use of the implications of the presented theories and the first three contributions (the fourth and fifth contribution).• The first contribution is a new conceptual model of a development effort that emphasizes tool integration.• The second contribution is a new reference model for tool integration in highly heterogeneous environments.• The third contribution consists of nine safety-related tool chain properties, i.e. properties of tool chains that could mitigate at least part of the risks introduced by tool integration.• The fourth contribution is a proposition on how to identify safety implications due to a high level of automation of tool integration.• The fifth contribution is a proposition for a new software tool qualification process.
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| 6. |
- Borg, Markus, et al.
(författare)
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Selecting component sourcing options : A survey of software engineering's broader make-or-buy decisions
- 2019
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Ingår i: Information and Software Technology. - : Elsevier B.V.. - 0950-5849 .- 1873-6025. ; 112, s. 18-34
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Tidskriftsartikel (refereegranskat)abstract
- Context: Component-based software engineering (CBSE) is a common approach to develop and evolve contemporary software systems. When evolving a system based on components, make-or-buy decisions are frequent, i.e., whether to develop components internally or to acquire them from external sources. In CBSE, several different sourcing options are available: (1) developing software in-house, (2) outsourcing development, (3) buying commercial-off-the-shelf software, and (4) integrating open source software components. Objective: Unfortunately, there is little available research on how organizations select component sourcing options (CSO) in industry practice. In this work, we seek to contribute empirical evidence to CSO selection. Method: We conduct a cross-domain survey on CSO selection in industry, implemented as an online questionnaire. Results: Based on 188 responses, we find that most organizations consider multiple CSOs during software evolution, and that the CSO decisions in industry are dominated by expert judgment. When choosing between candidate components, functional suitability acts as an initial filter, then reliability is the most important quality. Conclusion: We stress that future solution-oriented work on decision support has to account for the dominance of expert judgment in industry. Moreover, we identify considerable variation in CSO decision processes in industry. Finally, we encourage software development organizations to reflect on their decision processes when choosing whether to make or buy components, and we recommend using our survey for a first benchmarking.
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| 7. |
- Borg, Markus, et al.
(författare)
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Selecting Software Component Sourcing Options : Detailed Survey Description and Analysis
- 2018
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Component-based software engineering (CBSE) is a common approach to develop and evolve contemporary software systems. When evolving a system based on components, make-or-buy decisions are frequent, i.e., whether to develop components internally or to acquire them fromexternal sources. In CBSE, several different sourcing options are available: 1) developing software in-house, 2) outsourcing development, 3) buying commercial-off-the-shelf software, and 4) integrating open source software components. Unfortunately, there is little available research on howorganizations select component sourcing options (CSO) in industry practice. In this work, we seek to contribute empirical evidence to CSO selection. Method: We conduct a cross-domain survey on CSO selection in industry, implemented as an online questionnaire. Based on 188 responses, we find that most organizations consider multiple CSOs during software evolution, and that the CSO decisions in industry are dominated by expert judgment. When choosing between candidate components, functional suitability acts as an initial filter, then reliability is the most important quality. We stress that future solution-oriented work on decision support has to account for the dominance of expert judgment in industry. Moreover, we identify considerable variation in CSO decision processes in industry. Finally, we encourage software development organizations to reflect on their decision processes when choosing whether to make or buy components, and we recommend using our survey for a first benchmarking.
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| 8. |
- Dersten, Sara
(författare)
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Towards a guideline for refactoring of embedded systems
- 2012
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The electronics in automotive systems give great possibilities. It has contributed to environmental improvements through reduced emissions and reduced fuel consumption, safety, driver assistance, and quality through better diagnostic capabilities. Automotive systems are today distributed embedded systems that consist of several nodes that communicate with each other. The increasing possibilities have led to a situation where functions that used to be stand-alone, are today dependent on several inter-connected systems which all contribute to the desired functionality. This has increased the costs and the complexity to deal with the systems. The automotive industry is adopting a new open software architecture, called AUTOSAR, that is intended to reduce the complexity. AUTOSAR also gives possibilities for coping with large product ranges and for component sharing. The introduction of AUTOSAR is an example of an architecture change without modifying the external functionality. We have chosen to call such changes system refactoring. However, if the introduction of AUTOSAR is not successfully performed, there are risks for delayed development projects, which are costly for the automotive companies. Unfortunately, existing engineering standards and literature focus mostly on new product development and less on system re-factoring, and this gap needs to be filled. The goal of this research is to provide guidelines for refactoring, which provides support throughout the complete process of system architects in efforts to refactor the system. This thesis identifies the characteristics of refactoring processes. This is done by empirical studies of the drivers behind refactoring, the effects we can expect from refactoring, and the process activities and characteristics. The result can be used to create guidelines for improving the work of refactoring.
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| 9. |
- Rylander, David, 1981-
(författare)
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Productivity Improvements in Construction Site Operations through Lean Thinking and Wireless Real-Time Control
- 2014
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The purpose of a quarry is to extract rock material to deliver gravels, cement and asphalt to its customers. These products are important input to the construction and maintenance of road infrastructure, buildings and more. The operation of quarry and road work sites is similar to factory production, since it contains sequential production processes, tasks and activities to produce the output product. Compared to the factory, the quarry and road work processes are generally not synchronized and controlled towards the overall throughput in real-time. Some sites control parts of the production but do generally not utilize real-time technologies for the whole site and all its activities. This fact indicates a general improvement potential in increased productivity, but also unsolved challenges for the same reason. This thesis investigate how Lean thinking utilizing real-time control and wireless communication can be used to improve productivity and safety in the operation of quarry and road construction. The main overall contribution is the identified operational improvements, its use cases, the system design constraints and challenges as well as assessed impact in productivity, energy efficiency and safety if introducing wireless real-time control to the site operation. The results include the presentation and demonstration of a developed method based on Lean value stream mapping, for identifying wastes in sequential processes and activities including mobile machines. Further it investigates the performance and evaluates how the latest developments of wireless communication and vehicular ad-hoc networks (VANET) can be utilized within the quarry and road construction operation. The main system requirements and constraints are identified and the tradeoffs and gains in terms of system design, communication coverage, energy consumption and safety for the identified use cases are presented.
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| 10. |
- Rylander, David, 1981-
(författare)
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Productivity Improvements in Construction Transport Operation through Lean Thinking and Systems of Systems
- 2021
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The purpose of a quarry is to extract rock material to deliver gravel and raw material to its customers. The products can be further processed to e.g., extract minerals such as iron or to produce cement and asphalt. These products are an important input to the construction and maintenance of road infrastructure, buildings, and more. The operation of quarry and road work sites is similar to the manufacturing industry since it contains sequential processes to produce the output product. Within the operation, there are cyclic transport activities that in general are not synchronized and controlled in real-time towards the overall throughput. This fact indicates a potential to increase productivity but also points at unsolved challenges.This thesis investigates how Lean and systems thinking combined with real-time control and optimization technologies can be used to improve productivity and safety in the transport operation within quarry and road construction. The main contributions are the identified operational improvements, its use cases, the system design constraints, operational characteristics, and models as well as assessed impact in productivity, energy efficiency, and safety.The results include the development and demonstration of a method based on Lean value stream mapping, for identifying wastes in sequential processes and activities including mobile earthmoving machines. Operational wastes of 33% are presented from real world operations. Related fuel savings of 42% are measured in controlled environments. Further, the thesis presents and assesses a system design for transport optimization purpose. A study of how wireless communication and vehicular ad-hoc networks (VANET) can be utilized and its performance within the quarry and road construction operation is presented. The main system requirements and constraints are identified, and the trade-offs are discussed in terms of system design with a system of systems perspective. Energy consumption models are developed for optimization purposes and the key characteristics of real world operation is identified. Finally, a prototype system has been developed and tested in controlled and operative environments. In controlled trials, a fuel reduction of 20% for individual machines was obtained using the suggested optimization technique.
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