Model-based System Development Research Articles

Generating Obligations, Assertions and Tests from UI Models

Model-based development of interactive systems provides a number of benefits which can support the creation of robust and correct systems, particularly important when the interactive systems are safety-critical. Many different approaches have been proposed which target the models at different aspects of the development process (for example task analysis, interface layouts, functional behaviours etc.) and which can be used in different ways (verification of correctness, plasticity, usability). One of the aims for any modelling method should be simplicity - we are after all trying to hide complexity via abstraction in order to make reasoning about systems more tractable than working at the programming level. One of the challenges that exists however we do our modelling is ensuring the consistency between the model of the interface and interactivity and model of the functional behaviour of the system. This is primarily due to the different types of models that most naturally describe these different elements. In this paper we propose a method of tightening the integration of models of these different components of the system by generating obligations which explicitly describe the coupling of functional behaviour with interactive elements. We then show how these obligations can be used to support the development process during the programming and testing of the system.

Model-based collaborative development of manufacturing and control systems

This paper presents a collaborative model-based development method for a manufacturing system and its control system. The method is aimed towards improving the traditional manufacturing and control ...

Scenario-Based Modeling of the On-Board of a Satellite-Based Train Control System With Colored Petri Nets

For the goal of model-based system design and development, this paper exploits the formalism of colored Petri nets (CPNs) to model the on-board subsystem of a satellite-based train control system on the basis of scenarios. The Unified Modeling Language sequence diagrams, which are easily understood by customers, requirement engineers, and software developers, are used to represent scenarios as specification models. A scenario is a partial description of the system behavior, describing how users, system components, and the environment interact. Thus, scenarios need to be synthesized to obtain an overall system behavior. A large number of works have investigated scenario synthesis providing approaches or algorithms. These synthesis approaches and algorithms result in either Petri net models that are mainly suitable for scenario validation or other forms of behavior models (e.g., labeled transition systems and statecharts) that may be regarded as design models. Petri nets are well known for describing distributed and concurrent systems. Furthermore, numerous techniques, e.g., simulation, testing, state-space-based techniques, structural methods, and model checking, are currently available for analyzing PN models. Therefore, design models, which integrate all scenarios into a coherent whole suitable for further detailed design, in the form of Petri nets are promising. To this end, we present a top-down approach to establish hierarchical CPNs in accordance with specified scenarios (i.e., sequence diagrams). This approach makes use of explicitly labeling component states in the sequence diagrams to correlate scenarios. In addition, the techniques of state-space analysis and model-based testing are employed to verify the correctness and consistency of the CPN model with respect to standard and system-specific properties. The verification results show that our approach is desirable.

Model development guidelines for UML-RT: conventions, patterns and antipatterns

Software development guidelines are a set of rules which can help improve the quality of software. These rules are defined on the basis of experience gained by the software development community over time. This paper discusses a set of design guidelines for model-based development of complex real-time embedded software systems. To be precise, we propose nine design conventions, three design patterns and thirteen antipatterns for developing UML-RT models. These guidelines have been identified based on our analysis of around 100 UML-RT models from industry and academia. Most of the guidelines are explained with the help of examples, and standard templates from the current state of the art are used for documenting the design rules.

Model-Based Development of Control Systems for Forestry Cranes

Model-based methods are used in industry for prototyping concepts based on mathematical models. With our forest industry partners, we have established a model-based workflow for rapid development of motion control systems for forestry cranes. Applying this working method, we can verify control algorithms, both theoretically and practically. This paper is an example of this workflow and presents four topics related to the application of nonlinear control theory. The first topic presents the system of differential equations describing the motion dynamics. The second topic presents nonlinear control laws formulated according to sliding mode control theory. The third topic presents a procedure for model calibration and control tuning that are a prerequisite to realize experimental tests. The fourth topic presents the results of tests performed on an experimental crane specifically equipped for these tasks. Results of these studies show the advantages and disadvantages of these control algorithms, and they highlight their performance in terms of robustness and smoothness.

Application of System Design for Operational Effectiveness for Architectural Modeling of the SoS Relationship between Primary and Enabling Systems

Abstract Government mandates to control costs throughout the life cycle of a product necessitate a comprehensive architecture and methodology from design through operations and sustainment. The Systems Design for Operational Effectiveness (SDOE) model developed by Stevens Institute has become the basis of the Office of the Secretary of Defense (OSD) guidance with a focus on increasing reliability and reducing logistics footprint. The complexity of systems of systems approaches and model based systems development increases when both on-board and off-board enabling systems are considered. Models for both should be included in any comprehensive digital tapestry. There are multiple digital threads for life cycle data for the enabling systems to represent the necessary causal relationships between primary and enabling systems that determine operational effectiveness. To address this challenge, a reusable architecture and methodology for addressing this complexity is the first step. This framework can support definition and advanced application of data analytics and big data approaches to the digital threads that define the interaction between primary and enabling system, the industrial enterprise, and the deployed environment, providing the variables which contribute to operational outcomes, and effectiveness. This includes analysis of feedback from actual operations compared with planned suitability analysis during the design phase.

An architectural approach to the analysis, verification and validation of software intensive embedded systems

EAST-ADL is a domain specific Architecture Description Language (ADL) for safety-critical and software-intensive embedded systems. The language allows a formalized and traceable description of a wide range of engineering concerns throughout the entire lifecycle of system development. This makes it possible to fully utilize the leverage of state-of-the-art methods and tools for the development of correct-by-construction system functions and components in a seamless and cost efficient way. This paper focuses on the recent advancement of EAST-ADL in supporting an architecture-centric analysis, verification&validation of complex behaviors for the purposes of requirements engineering, application design, and safety engineering. The approach is architecture centric because all behavior descriptions are formalized and connected to a set of standardized design artifacts sitting at multiple levels of abstractions. We present the language design to support this, the theoretical underpinning and tool implementation. To show the capability of EAST-ADL, we also introduce an algorithm and its implementation for transforming the EAST-ADL behavior models to SPIN models for logic model checking. Exploiting mature state-of-the-art technologies from computer science, electronic engineering, and other related domains for a model-based incremental system development, the contribution enables the developers of embedded systems and software to maintain various engineering concerns coherently using EAST-ADL.

Multi-objective Architecture Optimisation Modelling for Dependable Systems

The design of dependable systems must address both cost and dependability (i.e. safety, reliability, availability and maintainability) concerns. For large systems, the design space of alternatives with respect to both dependability and cost is very large and automation is essential to explore this space. The model-based approach to the development and analysis of complex dependable systems is increasingly popular and recently, the Architecture Analysis and Design Language (AADL) has emerged as a potential future standard for model-based development of dependability-critical systems. The paper tackles the problem of describing, within an AADL model, the design space of alternative designs. A new AADL property set is proposed for modelling component and system variability for cost and dependability optimisation. The proposed method is illustrated with an example of an AADL model of a safety critical embedded system.

A methodology for the model-based development of mechanical systems: application to the CSeriesside stick controller

This paper introduces a methodology for the model-based development of mechanical systems at the aircraft manufacturer level. The presented methodology is applied to the CSeries side stick controll...

Using formal methods with SysML in aerospace design and engineering

Maintaining design consistency is a critical issue for macro-level aerospace development. The inability to maintain design consistency is a major contributor to cost and schedule overruns. By embedding The Systems Modeling Language (SysML) within a formal logic, formal methods can be used to maintain consistency as a design evolves. SysML, provided with a formal semantics, enables engineers to employ reasoning in the course of a typical model-based development process. Engineers can make use of formal methods within the context of current engineering practice and tools without needing to have special formal methods training. As component subsystems are introduced to refine a design, their assumptions are checked against current assumptions. If new assumptions do not introduce inconsistency, they are added to the model assumptions. If the assumptions render the design inconsistent, they are detected which minimizes potential rework. SysML has a demonstrated capability for top-to-bottom design refinement for large-scale aerospace systems. SysML does not have a formal logic-based semantics. The logical formalism within which SysML is embedded matches the informal semantic of SysML closely. The approach to integrating formal methods with SysML is illustrated with a typical macro-level aerospace design task. The design process produces a design solution which provably satisfies the top level requirements. The example provides evidence that coupling formal methods with SysML can realistically be applied to solve aerospace development problems. The approach results from a number of detailed design trades employing a model-based system development process which used SysML as the model integration framework.

Towards a Traceable Clinical Guidelines Application

The goal of this research is to provide an overall framework to enable model-based development of clinical guideline-based decision support systems (GBDSSs). The automatically generated GBDSSs are aimed at providing guided support to the physician during the application of guidelines and automatically storing guideline application data for traceability purposes. The development process of a GBDSS for a guideline is based on model-driven development (MDD) techniques which allow us to carry out such a process automatically, making development more agile and saving on human resource costs. We use UML Statecharts to represent the dynamics of guidelines and, based on this model, we use a MDD-based tool chain to generate the guideline-dependent components of each GBDSS in an automatic way. In particular, as for the traceability capabilities of each GBDSS, MDD techniques are combined with database schema mappings for metadata management in order to automatically generate the GBDSS-persistent component as one of the main contributions of this paper. The complete framework has been implemented as an Eclipse plug-in named GBDSSGenerator which, starting from the statechart representing a guideline, allows the development process to be carried out automatically by only selecting different menu options the plug-in provides. We have successfully validated our overall approach by generating the GBDSS for different types of clinical guidelines, even for laboratory guidelines. The proposed framework allows the development of clinical guideline-based decision support systems in an automatic way making this process more agile and saving on human resource costs.

Model-based Development of Self-organizing Earthquake Early Warning Systems

Model-based Development of Self-organizing Earthquake Early Warning Systems

Bridging the requirements–implementation modeling gap with object–process methodology

A model-based system development cycle involves two semantically distinct aspects: the requirements specification and the implementation model. Due to the conceptual and semantic differences between these two major system lifecycle stages, the transition from requirements to implementation is inherently a noncoherent process. Consequently, the system requirements are not faithfully transformed into the working system. This paper introduces an effective solution via an Integrated Modeling Paradigm (IMP) that combines the requirements and implementation domain models into a unified system model that continuously represents the system as it evolves. The IMP was implemented in an Object–Process Methodology (OPM) development environment. This implementation reinforces OPM with the capability to bridge the significant conceptual gap that lies right at the heart of the development process. A user survey has shown that this OPM-based solution is easy to use and can indeed help bridge the information gap, yielding a better match between the required and implemented systems than the currently accepted practice.

Prerequisites for model-based development of Autosar systems

The Autosar initiative and the results of its work have established essential preconditions for mastering the complexity of electronic and software-driven systems today and in the future. However, development of Autosar compliant components means new requirements to development methods. Use of a model-based approach is possible only if the modeling language provides for definition of Autosar specific architecture and functional elements. Telelogic describes a way towards an Autosar compliant development environment based on a power window subsystem.

A hybrid framework for resource verification in executable model-based embedded system development

In this work, we consider the integration of resource safety verification into a design methodology for development of verified and robust real-time embedded systems. Resource-related concerns are not closely linked with current xUML model-based software development although they are critical for embedded systems. Our work employs the hybrid verification framework combining static resource analysis and run-time monitoring schemes.

Model-based design and verification—State of the art from Galileo constellation down to small university satellites

Since 2001 EADS Astrium GmbH has implemented a model-based system simulation infrastructure for support of spacecraft development, onboard software verification and spacecraft design validation. Corresponding thereto an engineering process has been established, allowing development and full design validation of spacecrafts without necessity of engineering models on spacecraft level. This simulation infrastructure is called “model-based development and verification environment” (MDVE). Major benefit of model-based system development applying MDVE is the early possibility for simulated satellite mission operations, using real onboard software in the virtual satellite, even before availability of real hardware. This represents an outstanding support to system design qualification and performance verification. MDVE technology application, however, is not limited to commercial and large-scale spacecrafts. In a close partnership with Universität Stuttgart, EADS Astrium also sponsored an MDVE installation to the Institute of Space Systems (IRS) for the small-satellite program Flying Laptop, which is the first micro-satellite under development of IRS. This paper presents the span of benefits of model-based engineering with MDVE in application from small satellites up to spacecraft constellations like Galileo. The MDVE hardware and software concepts, typical testbench constellations and satellite design process characteristics are presented with application examples given both from the micro-satellite Flying Laptop as well as from the Galileo program.

Accounting for the Development Costs of Internal-Use Software

In this paper, we evaluate accounting practices for internal-use software expenditures. Statement of Position No. 98-1 (SOP No. 98-1) requires expensing certain costs and capitalizing others. We argue that current accounting practice does not allow enough capitalization, since costs incurred during the systems analysis stage of model-based systems development are expensed regardless of whether they create future benefits. The quest for uniformity in accounting treatment in the form of a single rule for multiple economic phenomena (i.e., treating all systems acquisition and development methods the same) results in reduced ability to reflect economic differences between systems acquisition and development methods. To illustrate, we provide an example of the differential effects of adopting SOP No. 98-1 for firms using different development approaches. Under the SOP, “Analysis” costs are expensed. Under model-based approaches, especially those with downstream effects, these Analysis costs are assets, since the reason for these approaches is their ability to re-use models and objects developed in Analysis. Furthermore, since these costs tend to be relatively higher for companies leveraging these models and objects, the SOP has the effect of ignoring the future value associated with these models and objects. We propose a solution that is principles-based and provides a framework specifying the conditions under which capitalization or expensing should occur for internally developed software.

Model-Based System Development for Asynchronous Distance Learning

The innovation and diversification of development in multimedia technology and network infrastructures have brought a significant impact to education, especially for distance learning. This paper presents a model-based asynchronous distance learning system development that consists of a presentation semantic model called the multimedia augmented transition network (MATN) model and an asynchronous distance learning system called the Java-based Integrated Asynchronous Distance Learning (JIADL) system. The MATN model is powerful in modeling the synchronization and quality-of-service (QoS) for distance learning multimedia presentations. The JIADL system can support diverse asynchronous distance learning services by integrating RealPlayer and Java technology to augment the superiority of both models. A course sample is used to illustrate and validate the effectiveness of the system. How to use the MATN model to model the diversity requirements of a distance learning multimedia presentation is also discussed. Furthermore, the initial experimental results show that our system is cost effective and has a wide range of applications.

Model-based system development

Distributed embedded computer systems are the key enablers of X-by-wire systems and control system functions. While developers can validate the correct operation of the communication and operating systems and the silicon implementations - the basis of embedded computer systems - once and for all, they cannot validate the application-dependent software and data structures in these systems in the same manner. The developer must configure the communication system for the respective application, create middleware code to access the communication system, and, last but not least, implement the application software. Because this is necessary for every new application, we need a well-defined process and a complementary set of tools to minimize error and support a high-quality development life cycle. We propose a model-based process - the "A" process. It consists of a sequence of models, each of which serves a specific purpose and hence contains only those pieces of information it requires for this purpose. The models are linked to each other by process transitions that either add information to or extract information from their predecessors. The A process guides the developer from one model to the next and is supported by a set Of tools. In this article, we discuss development process models in general, and our model-based process in particular.

Compositional Comparison of Formal Software Specifications Using Transformation Systems

Abstract. In a model-based software systems development formal specifications of the components of the system are developed. Thereby different specifications are used to represent the different aspects or views of the components, possibly following different paradigms. These heterogeneous viewpoint specifications have to be integrated in order to obtain a consistent global specification of the whole system. In this paper transformation systems are introduced as a common semantic domain where specifications written in different languages can be interpreted and formally compared. A transformation system is a transition system where the transitions are labelled by sets of actions and the states are labelled by algebras representing the data states. Development relations and composition operations for transformation systems are investigated, and it is shown that compatible local developments of components induce a global development of their composition. As an application two specifications of the alternating bit protocol are formally compared component-wise, one given in the process calculus CCS, the other one in the parallel programming language UNITY.