SOFTWARE TESTABILITY MEASURE FOR SAE ARCHITECTURE ANALYSIS AND DESIGN LANGUAGE (AADL)SOFTWARE TESTABILITY MEASURE FOR SAE ARCHITECTURE ANALYSIS AND DESIGN LANGUAGE (AADL)

Testability is an important quality attribute of software, especially for critical systems such as avionics, medical, and automotive. Improvement in the early testability of software architecture, the first artifact of the software system, will help reduce issues and costs later in the development process. AADL, an architecture analysis description language suitable for critical embedded, real-time systems, can be used for design documentation, analysis and code generation. Because the capability of AADL can be extended, it is possible to add new analyses to its core language. Tools such as the Open Source AADL Tool Environment (OSATE) provide plugins for processing AADL models. Although adding new plugins in OSATE extends AADL, there currently exists no AADL extension for testability measurement. The purpose of this thesis is to propose such a method to measure the testability of AADL models as well as to develop a testability plugin in OSATE. Much research has been conducted on testability of hardware, software and embedded systems, resulting in several approaches for measuring this quality attribute. Among them, the approach measuring testability as a product of controllability and observability using information transfer graph (ITG) is the most applicable for measuring the testability of AADL models. This thesis proposes a method applying this approach to AADL models. A complete testability measure plugin for OSATE was developed based on this approach and detailed examples are given in this thesis to demonstrate its applicability

Customized Software in Distributed Embedded Systems: ISOBUS and the Coming Revolution in Agriculture

The electrification of agricultural equipment has been evolving for many years and in some ways is lagging behind other industries. However this strategy of following the lead of other industries now offers Ag the opportunity to move forward at a revolutionary pace. Network standards defined by the Society of Automotive Engineers (SAE) and the International Organization for Standardization (ISO) committees are the basis for defining a rulebook for this industrystandardizing worldwide electronics interoperability. ISOBUS (ISO 11783) which defines a physical standard between tractors and implements will be an important enabler for most new product definitions. The foundation of this coming revolution will be provided through software. This paper outlines the electronics hardware and software architecture for off-road vehicles that allows for implementation of customized machine control features. There are several key areas discussed. The first enabler for this revolution is a software development and delivery system that defines a design methodology for creating and delivering software modules for a distributed set of controllers. This design methodology presents two advantages that today’s modern electronic technologies can deliver: 1) Customization with commodity hardware and 2) Service without replacing hardware parts anywhere in the world. The second enabler for this machine revolution is an ‘agile’ process to develop the software. Many product ideas are being valuated through a trial and error and continuous improvement process. Software will play an important enabler for these product definitions. A comparison between the worldwide trend for software processes, the Capability Maturity Model (CMM), and what type of process would fit the offroad industry is based around the maturity of the new product ideas. The strong supply chain link between dealers and customers for off-road machines, coupled with the emerging awareness of electronic functions and controls, sets a basis for a specialized software development process. An important enabler for this ‘agile’ process is the re-use of code and incremental testing with reviews. The history of the off-road machine business has been based on proven designs and long times between model updates. However, the worldwide adoption of the ISOBUS standard is poised to change this history. ISOBUS is not only establishing an open system for interoperability, it is establishing a sequence of features for diagnostics, sequenced operations, and information management. As customers discover these capabilities, they will expect them to be further advanced and customized for their specific needs. This requires adding agility into the proven durable processes so that manufacturers can respond faster to these growing needs. Electronics, and especially well-planned software systems, offer an agile technology for meeting this coming need. This paper presents the benchmarking of various embedded software development projects relating project content, project rigor, and quality. From this, insights into maintaining quality are gained in order to include agility into a durable development project. Also, risk and rewards of leveraging low cost country software development skills are addressed to stretch resources or even develop common resources for software systems

An Adaptive Design Methodology for Reduction of Product Development Risk

Embedded systems interaction with environment inherently complicates understanding of requirements and their correct implementation. However, product uncertainty is highest during early stages of development. Design verification is an essential step in the development of any system, especially for Embedded System. This paper introduces a novel adaptive design methodology, which incorporates step-wise prototyping and verification. With each adaptive step product-realization level is enhanced while decreasing the level of product uncertainty, thereby reducing the overall costs. The back-bone of this frame-work is the development of Domain Specific Operational (DOP) Model and the associated Verification Instrumentation for Test and Evaluation, developed based on the DOP model. Together they generate functionally valid test-sequence for carrying out prototype evaluation. With the help of a case study 'Multimode Detection Subsystem' the application of this method is sketched. The design methodologies can be compared by defining and computing a generic performance criterion like Average design-cycle Risk. For the case study, by computing Average design-cycle Risk, it is shown that the adaptive method reduces the product development risk for a small increase in the total design cycle time.Comment: 21 pages, 9 figure

Safety-Critical Systems and Agile Development: A Mapping Study

In the last decades, agile methods had a huge impact on how software is developed. In many cases, this has led to significant benefits, such as quality and speed of software deliveries to customers. However, safety-critical systems have widely been dismissed from benefiting from agile methods. Products that include safety critical aspects are therefore faced with a situation in which the development of safety-critical parts can significantly limit the potential speed-up through agile methods, for the full product, but also in the non-safety critical parts. For such products, the ability to develop safety-critical software in an agile way will generate a competitive advantage. In order to enable future research in this important area, we present in this paper a mapping of the current state of practice based on {a mixed method approach}. Starting from a workshop with experts from six large Swedish product development companies we develop a lens for our analysis. We then present a systematic mapping study on safety-critical systems and agile development through this lens in order to map potential benefits, challenges, and solution candidates for guiding future research.Comment: Accepted at Euromicro Conf. on Software Engineering and Advanced Applications 2018, Prague, Czech Republi

Influential factors of aligning Spotify squads in mission-critical and offshore projects – a longitudinal embedded case study

Changing the development process of an organization is one of the toughest and riskiest decisions. This is particularly true if the known experiences and practices of the new considered ways of working are relative and subject to contextual assumptions. Spotify engineering culture is deemed as a new agile software development method which increasingly attracts large-scale organizations. The method relies on several small cross-functional self-organized teams (i.e., squads). The squad autonomy is a key driver in Spotify method, where a squad decides what to do and how to do it. To enable effective squad autonomy, each squad shall be aligned with a mission, strategy, short-term goals and other squads. Since a little known about Spotify method, there is a need to answer the question of: How can organizations work out and maintain the alignment to enable loosely coupled and tightly aligned squads? In this paper, we identify factors to support the alignment that is actually performed in practice but have never been discussed before in terms of Spotify method. We also present Spotify Tailoring by highlighting the modified and newly introduced processes to the method. Our work is based on a longitudinal embedded case study which was conducted in a real-world large-scale offshore software intensive organization that maintains mission-critical systems. According to the confidentiality agreement by the organization in question, we are not allowed to reveal a detailed description of the features of the explored project