Software engineering processes for self-adaptive systems

In this paper, we discuss how for self-adaptive systems some activities that traditionally occur at development-time are moved to run-time. Responsibilities for these activities shift from software engineers to the system itself, causing the traditional boundary between development-time and run-time to blur. As a consequence, we argue how the traditional software engineering process needs to be reconceptualized to distinguish both development-time and run-time activities, and to support designers in taking decisions on how to properly engineer such systems. Furthermore, we identify a number of challenges related to this required reconceptualization, and we propose initial ideas based on process modeling. We use the Software and Systems Process Engineering Meta-Model (SPEM) to specify which activities are meant to be performed off-line and on-line, and also the dependencies between them. The proposed models should capture information about the costs and benefits of shifting activities to run-time, since such models should support software engineers in their decisions when they are engineering self-adaptive systems

Using Acceptors as Transducers

We wish to use a given nondeterministic two-way multi-tape acceptor as a transducer by supplying the contents for only some of its input tapes, and asking it to generate the missing contents for the other tapes. We provide here an algorithm for assuring beforehand that this transduction always results in a finite set of answers. We also develop an algorithm for evaluating these answers whenever the previous algorithm indicated their finiteness. Furthermore, our algorithms can be used for speeding up the simulation of these acceptors even when not used as transducers

Concept-Based Partitioning for Large Multidomain Multifunctional Embedded Systems

Hardware-software partitioning is an important phase in embedded systems. Decisions made during this phase impact the quality, cost, performance, and the delivery date of the final product. Over the past decade or more, various partitioning approaches have been proposed. A majority operate at a relatively fine granularity and use a low-level executable specification as the starting point. This presents problems if the context is families of industrial products with frequent release of upgraded or new members. Managing complexity using a low-level specification is extremely challenging and impacts developer productivity. Designing using a high-level specification and component-based development, although a better option, imposes component integration and replacement problems during system evolution and new product release. A new approach termed Concept-Based Partitioning is presented that focuses on system evolution, product lines, and large-scale reuse when partitioning. Beginning with information from UML 2.0 sequence diagrams and a concept repository concepts are identified and used as the unit of partitioning within a specification. A methodology for the refinement of interpart communication in the system specification using sequence diagrams is also presented. Change localization during system evolution, composability during large-scale reuse, and provision for configurable feature variations for a product line are facilitated by a Generic Adaptive Layer (GAL) around selected concepts. The methodology was applied on a subsystem of an Unmanned Aerial Vehicle (UAV) using various concepts which improved the composability of concepts while keeping performance and size overhead within the 2% range