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In many embedded systems types the separation process for deploying the applications as software and hardware executable units, called partitioning is crucial. This is due to the fact that partitioning decisions impact the overall life cycle of the systems. In industry it is common practice to take partitioning decisions in an early stage of the design, based on hardware and software designers expertise. We propose a new methodology as a combination of modelbased and component-based approaches which enables a late partitioning decisions based on high level system requirements and project constrains. The final partitioning is decided based on a multi-property analysis approach. Here, we focus on the formalization of the overall process and in particular on the definition of a comprehensive system metamodel. This is meant to support modelling approaches suitable for enabling both the partitioning and reuse. An industrial case study is used to illustrate the approach.

Growing advances in hardware technologies are enabling significant improvements in application performance by the deployment of components to dedicated executable units. This is particularly valid for Cyber Physical Systems in which the applications are partitioned in HW and SW execution units. The growing complexity of such systems, and increasing requirements, both project- and product-related, makes the partitioning decision process complex. Although different approaches to this decision process have been proposed during recent decades, they lack the ability to provide relevant decisions based on a larger number of requirements and project/business constraints. A sound approach to this problem is taking into account all relevant requirements and constraints and their relations to the properties of the components deployed either as HW or SW units. A typical approach for managing a large number of criteria is a multicriteria decision analysis. This, in its turn, requires uniform definitions of component properties and their realization in respect to their HW/SW deployment. The aim of this paper is twofold: a) to provide an architectural metamodel of component-based applications with specifications of their properties with respect to their partitioning, and b) to categorize component properties in relation to HW/SW deployment. The metamodel enables the transition of system requirements to system and component properties. The categorization provides support for architectural decisions. It is demonstrated through a property guideline for the partitioning of the System Automation and Control domain. The guideline is based on interviews with practitioners and researchers, the experts in this domain.

We focus here on the application of multi critera decision analysis (MCDA) techniques in hardware/software partitioning activities to be used in the design and deployment of embedded systems. Our goal is to identify the best existing methods and tools suitable to support the approach we have taken for the partitioning process. We provide this via a survey of the most well-known MCDA methods and tools (for a specific class of MCDA methods called multi attribute decision making. We identify a set of criteria that need to be addressed, in some way, by the methods, and implemented by related tools. These "11-suitability criteria" help us in deciding the appropriateness of the analysed methods and tools for the envisaged partitioning approach. In brief, we are interested that the MCDA methods are taking into account multiple extra-functional properties, expressed by a variety of types, with possible missing values, should enable dependency handling, decision traceability, etc. The conclusion is that there are criteria that are not fulfilled by any of the methods, and hence there is no method or tool that can directly used for the partitioning. However, the results shows the potential of using MCDA in the partitioning process and provide a good starting point for future research activities.

Modern embedded systems utilize the advances in heterogeneous platforms that enable implementing functions in software (SW) and hardware (HW) components. A proper configuration of SW and HW components can significantly improve the values of the extra-functional properties such as performance and energy savings. However, due to increasing application complexity, it is difficult to find the best combination of HW and SW components. The problem basically boils down to calculate, for a given architecture, the system properties from the components' ones. In this paper, we address the problem of composability of EFPs at system level. Although in general this is not a solvable problem, we present that, under strictly specified constraints, it is possible to compose the system EFPs starting from the component ones. We start by detailing constraints related to the system architecture, platform and process development and, based on these constraints, we provide composition rules for different types of EFPs. We demonstrate the results through an industrial example.

Platforms with different computation resource, e.g. CPUs and FPGAs, known as heterogeneous platforms, are becoming one of the first choices to deploy performance-requiring embedded applications. On this technology, functionalities can be implemented either as hardware (HW) or software (SW) components. In this paper, we propose a new methodology, called MultiPar, which is able to provide optimal partitioning solution(s) with respe system properties based on Multiple Criteria Decision Analysis. We provide an overview of the methodology. MultiPar is based on a bottom-up principle, first, to find the most suitable SW and HW implementations based on their properties, and then applying compositional rules and other means uses the system properties to find the best partitioning solutions. In addition, we show the feasibility of the proposed methodology through an industrial case, and in particular validation of the compositional rules for some properties used in the partitioning decision process. MultiPar methodology is implemented as a tool, which is used in the validation process.

Decision process is often based on multi-faceted and mutually opposing criteria. In order to provide rigorous techniques for problem structuring and criteria aggregation used for classification and ranking of alternatives, Multiple Criteria Decision Analysis (MCDA) has been used as a method to achieve architectural decisions. Even though it has already been argued in literature that MCDA essentially depends on value systems of decision-makers, it is a question how the decision result reflects a particular criterion, requirement or a particular decision. This is especially true if a criterion is not precisely specified. In this paper we analyse the ethical aspects of MCDA. In our analysis we argue that it is in the long run necessary to make value basis of decision-making and ethical considerations explicit and subject for scrutiny. As a support to encourage introduction of transparent value-based deliberation we propose an extended MCDA scheme that would explicitly take into account ethical analysis. As an illustration, we present an industrial case study for the Software (SW)/Hardware (HW) partitioning of a wind turbine application in which different decisions can be taken, depending on the ethical aspects.