Application of Systems Modeling Language (SySML) for Cognitive Work Analysis in Systems Engineering Design Process

At present time most system engineers do not have access to cognitive work analysis knowledge or training in terms that they could understand and apply in the system design process. This may lead to specifying systems requirements that do not account for cognitive strengths and limitations of the prospective users. This paper proposes integration of cognitive work demands in the systems engineering process through development of a Cognitive Work Analysis (CWA) framework and a Tutorial using Systems Modeling Language (SysML). The CWA framework provides a structured approach for defining, managing, organizing, and modeling cognitive work requirements in systems engineering process

Clafer: Lightweight Modeling of Structure, Behaviour, and Variability

Embedded software is growing fast in size and complexity, leading to intimate mixture of complex architectures and complex control. Consequently, software specification requires modeling both structures and behaviour of systems. Unfortunately, existing languages do not integrate these aspects well, usually prioritizing one of them. It is common to develop a separate language for each of these facets. In this paper, we contribute Clafer: a small language that attempts to tackle this challenge. It combines rich structural modeling with state of the art behavioural formalisms. We are not aware of any other modeling language that seamlessly combines these facets common to system and software modeling. We show how Clafer, in a single unified syntax and semantics, allows capturing feature models (variability), component models, discrete control models (automata) and variability encompassing all these aspects. The language is built on top of first order logic with quantifiers over basic entities (for modeling structures) combined with linear temporal logic (for modeling behaviour). On top of this semantic foundation we build a simple but expressive syntax, enriched with carefully selected syntactic expansions that cover hierarchical modeling, associations, automata, scenarios, and Dwyer's property patterns. We evaluate Clafer using a power window case study, and comparing it against other notations that substantially overlap with its scope (SysML, AADL, Temporal OCL and Live Sequence Charts), discussing benefits and perils of using a single notation for the purpose

SysML Modeling For Embedded Systems Design Optimization: A Case Study

Model-Based Systems Engineering (MBSE) with the SysML language allows the designer to include requirement capture and design representation in a single model. This paper proposes a methodology to obtain the best design alternative, from a SysML design, by using multi-objective optimization techniques. A SysML model is extended with stereotypes, objective functions, variability and constraints. Then an integer representation of the problem can be generated and solved as a constraint satisfaction problem (CSP). The paper illustrates our methodology using an Embedded Cognitive Safety System (ECSS) design. From a component repository and redundancy alternatives, the best design alternatives are generated, to minimize the total cost and maximize the estimated system reliability

Specifying Space Defense Operator Interfaces through the Application of Cognitive Systems Engineering and Prototyping

The Department of Defense needs better tools to support its operators as they strive to defend its space assets. The growing sophistication of anti-satellite weapons increasingly challenges the nation’s orbital communications and surveillance infrastructure. Operators face difficulties gathering useful information and dealing with the complexity of potential enemy actions. This research applied cognitive systems engineering and ecological interface design (EID) methodologies to create a prototype space mission management tool that enhances operator situation awareness and decision-making ability. Applied cognitive task analysis interviews were used to document space operator decision-making in their domain. Model-based systems engineering was applied to integrate work domain concepts into system models. EID methods were applied to inform user interface designs that support high-level decision making in addition to low-level tasks. User interface concepts were developed using rapid prototyping software, Axure 9.0, to satisfy the system requirements. The software prototypes were shown to space operators and assessed for validity. This process demonstrated how cognitive systems engineering can be used to derive system requirements and create system designs, the elements of which can be captured in a systems model and traced to operator goals, resulting in systems that are more capable of supporting operator needs in challenging environments

Model-based training of manual procedures in automated production systems

Maintenance engineers deal with increasingly complex automated production systems (aPSs). Such systems are characterized by an increasing computerization or the addition of robots that collaborate with human workers. The effects of changing or replacing components of such systems are difficult to assess since there are complex interdependencies between process parameters and the state of the components. This paper proposes a model-based training system that visualizes these interdependencies using domain-independent SysML models. The training system consists of a virtual training system for initial training and an online support system for assistance during maintenance or changeover procedures. Both systems use structural SysML models to visualize the state of the machine at a certain step of a procedure. An evaluation of the system in a changeover procedure against a paper-based manual showed promising results regarding effectiveness, usability and attractiveness.Comment: 25 pages, https://www.sciencedirect.com/science/article/pii/S095741581830080

Industrial Adoption of Model-Based Systems Engineering: Challenges and Strategies

As design teams are becoming more globally integrated, one of the biggest challenges is to efficiently communicate across the team. The increasing complexity and multi-disciplinary nature of the products are also making it difficult to keep track of all the information generated during the design process by these global team members. System engineers have identified Model-based Systems Engineering (MBSE) as a possible solution where the emphasis is placed on the application of visual modeling methods and best practices to systems engineering (SE) activities right from the beginning of the conceptual design phases through to the end of the product lifecycle. Despite several advantages, there are multiple challenges restricting the adoption of MBSE by industry. We mainly consider the following two challenges: a) Industry perceives MBSE just as a diagramming tool and does not see too much value in MBSE; b) Industrial adopters are skeptical if the products developed using MBSE approach will be accepted by the regulatory bodies. To provide counter evidence to the former challenge, we developed a generic framework for translation from an MBSE tool (Systems Modeling Language, SysML) to an analysis tool (Agent-Based Modeling, ABM). The translation is demonstrated using a simplified air traffic management problem and provides an example of a potential quite significant value: the ability to use MBSE representations directly in an analysis setting. For the latter challenge, we are developing a reference model that uses SysML to represent a generic infusion pump and SE process for planning, developing, and obtaining regulatory approval of a medical device. This reference model demonstrates how regulatory requirements can be captured effectively through model-based representations. We will present another case study at the end where we will apply the knowledge gained from both case studies to a UAV design problem

UML Based Requirement Management Process in Mobile Multimedia Software Projects

Requirements management is an important sub-process in software development lifecycle. Its purpose is to assure that the project outcome meets the expectations of the customers and other internal or external stakeholders. Without a proper requirement management projects will certainly fail to deliver within the promised time, budget, scope and quality. To better cope with the requirement related challenges extended Unified Modeling Language (UML) methodologies were studied. These UML extensions can be used to model the business processes and requirements. Currently the UML is extensively used in the industry to design software systems. But when used also to model the business processes and requirements a number of benefits over the tradional way of managing requirements result: tracebility from requirements to design and to implementation is much easier, communication of complex issues and their relation to requirements is much enhanced, understanding of the system behaviour is distributed in the project team and the system model describing the product is more complete, integrated and accurate. As a result of this thesis new type of requirement management process was created. This process is embeddable and applicable to any implementation language and many types of development processes and projects. To succesfully deploy such a process one has to have the necessary tool support and the organisation must be UML literate.Vaatimushallinta on tärkeä aliprosessi ohjelmistojen kehityksessä. Sen tarkoituksena on varmistaa, että projektin tuotos vastaa asiakkaan ja muiden sisäisten ja ulkoisten projektiin osallisten sovittuja odotuksia. Ilman toimivaa vaatimushallintaprosessia projektit eivät onnistu pysymään luvatuissa aika, budjetti, laajuus ja laatukehyksissään. Vaatimuksiin liittyvien haasteiden ratkaisemiseksi tutkittiin viimeaikaisia laajennuksia UML kuvauskieleen. Näitä UML laajennuksia käyttämällä voidaan mallintaa asiakkaan liiketoimintaprosessit ja vaatimukset. Nykyisin UML:ää käytetään laajasti ohjelmistonsuunnittelussa. Mutta kun sitä käytetään myös mallintamaan liiketoimintaprosesesseja ja vaatimuksia siitä seuraa useita parannuksia perinteiseen tapaan hallita vaatimuksia: vaatimusten jäljittäminen toteutukseen on paljon helpompaa, ongelmallisten asioiden ja niiden vaatimusrelaation kommunikointi on tehokkaampaa, järjestelmän kokonaisuuden hahmottaminen on jakautunut laajemmalle projektitiimissä ja toimitettavaa järjestelmää kuvaavasta mallista tulee kattavampi, integroiduimpi ja enemmän todellisuutta vastaava. Tutkimuksen tuotoksena on uudentyyppinen vaatimushallintaprosessi. Tämä aliprosessi on sulautettavissa ja sovellettavissa mille tahansa ohjelmointikielelle. Se sopii monentyyppisiin ohjelmistonkehitysprosesseihin ja projekteihin. Organisaation täytyy myös hallita UML ja siihen liittyvien työkalujen käyttö