Systems Engineering Chapter 2

Chapter 2 Systems Engineering 1  Overview Systems engineering is the application of scientific and engineering principles to define the requirements, functions, and performance of a system, as well as to manage its life cycle. Systems engi...

Chapter 2 Systems Engineering 1  Overview Systems engineering is the application of scientific and engineering principles to define the requirements, functions, and performance of a system, as well as to manage its life cycle. Systems engineering supports systems integration by providing methods and tools for analysing, verifying, and validating the system's behaviour and performance. ▪ Learning the concepts and techniques of system engineering can enhance our ability to design, implement, test, evaluate, and maintain integrated systems that meet the expectations and needs of their intended users and stakeholders. ▪ Systems engineering follows a systematic approach that consists of several processes and standards. Some of the main processes are: stakeholder analysis, requirements definition, system definition, system design and tradespace exploration, system implementation, system testing, system deployment, and system operation. 2  Stakeholder Analysis Stakeholder analysis is a process of identifying and evaluating the interests, needs, and expectations of the people or groups who are affected by or can influence a project, program, or policy. Stakeholder analysis helps to ensure that the project objectives and outcomes are aligned with the stakeholder priorities and values, and that potential conflicts or risks are anticipated and mitigated. Stakeholder analysis also facilitates communication, engagement, and collaboration among the stakeholders throughout the project lifecycle. A stakeholder analysis typically involves the following steps: Identify the key stakeholders and their roles and responsibilities in relation to the project. Assess the level of influence, interest, and impact of each stakeholder on the project, using a stakeholder matrix or a similar tool. Determine the stakeholder expectations, needs, and concerns regarding the project scope, objectives, benefits, risks, and issues. 3  Stakeholder Analysis Analyse the potential opportunities and challenges for engaging with each stakeholder group, and develop strategies to address them. Prioritize the stakeholders based on their importance and urgency for the project success, and plan how to communicate and involve them accordingly. Monitor and review the stakeholder feedback and satisfaction throughout the project implementation and evaluation, and adjust the stakeholder management plan as needed. 4  System Requirements Definition Requirements definition is the process of systematically determining and documenting the necessary characteristics and constraints of a system, based on the stakeholder needs and expectations. Requirements definition establishes a clear and unambiguous baseline for the system design, implementation, testing, and validation. Requirements can be categorized into functional and non-functional, where functional requirements describe the system's intended actions, while non-functional requirements define the system's performance, reliability, usability, and other quality attributes. The main steps in the requirements definition process include: Elicit the stakeholder needs and expectations through interviews, workshops, surveys, or other techniques. Analyse and prioritize the stakeholder inputs, considering the project goals, constraints, and risks. Translate the stakeholder inputs into specific, measurable, achievable, relevant, and time-bound 5 (SMART) requirements.  System Requirements Definition Organize the requirements into a structured hierarchy or a traceability matrix, to facilitate the system decomposition and allocation. Validate the requirements with the stakeholders, to ensure their correctness, completeness, and consistency. Manage the requirements changes and updates, to maintain the system baseline and to avoid scope creep and requirements volatility. 6  System Definition - System definition is a critical process in systems engineering that sets the technical requirements and functional architecture of a system. The essential goal of system definition is to ensure that the system meets operational needs and complies with technical specifications. - The process involves identifying stakeholders' needs and expectations, setting system boundaries and scope, and breaking down the system into subsystems and components. Functions and performance are allocated to each element of the system, with defined interfaces and interactions among them. - System definition aims to provide a comprehensive and coherent description of the system's intended functions, operation, and its verification and validation methods. - The process is iterative and collaborative, requiring constant communication and feedback among system engineers, customers, users, and other stakeholders. 7  System Design and Tradespace Exploration System design and tradespace exploration involve developing and evaluating multiple design alternatives to find the optimal solution that meets the system requirements and constraints while maximizing the overall performance, value, and stakeholder satisfaction. Tradespace exploration allows for the identification of trade-offs between different design attributes, such as cost, schedule, risk, and quality, to support informed decision-making and risk management. The main steps in the system design and tradespace exploration process include: Generate multiple design alternatives, based on the system requirements, architecture, and constraints. Develop models, simulations, or prototypes to represent and analyse the design alternatives and their performance, risks, and interdependencies. Apply multi-criteria decision analysis, optimization, or other methods to evaluate and compare the design alternatives, considering the stakeholders' preferences, values, and uncertainties. 8  System Design and Tradespace Exploration Select the preferred design alternative, based on the evaluation results, the project goals, and the stakeholders' consensus. Perform sensitivity and robustness analysis to assess the impact of the assumptions, parameters, and uncertainties on the design choice and the system outcomes. Iterate and refine the design alternative, as needed, to accommodate the changes in the requirements, constraints, or environment. 9  System Implementation System implementation is the process of transforming the system design and specifications into a physical, operational, and functional entity. System implementation involves the integration of subsystems, components, hardware, software, and human elements, as well as the verification and validation of the system's performance, reliability, and compliance with the requirements and standards. The main steps in the system implementation process include: Develop detailed design documents, plans, and procedures for the system assembly, installation, and configuration. Procure or manufacture the required subsystems, components, materials, and equipment, according to the quality and safety specifications. Assemble, integrate, and test the subsystems and components, to ensure their proper functioning, compatibility, and interoperability. Conduct system-level verification and validation activities, such as inspections, analyses, demonstrations, and tests, to confirm that the system meets the specified requirements and 10 criteria.  System Testing System testing is the process of evaluating the system's performance, functionality, and compliance with the requirements and standards under various conditions and scenarios. System testing aims to identify and mitigate potential defects, risks, and limitations before the system's deployment and operation. System testing can be performed at different levels of integration, from unit testing of individual components to system integration testing of the whole system. The main steps in the system testing process include: Develop a test plan and test cases, based on the system requirements, design, and risks. Prepare the test environment, test data, and test tools, to simulate the system's operational context and constraints. Execute the test cases, record the test results, and analyze the test outcomes to identify discrepancies, anomalies, or failures. Report the test findings, recommend corrective actions, and track the resolution of the issues and the retesting of the system. Evaluate the test coverage, effectiveness, and efficiency, to assess the system's readiness for deployment and operation. 11  System Deployment System deployment is the process of transitioning the system from the development and testing phases to the operational environment and making it available for use by the intended users and stakeholders. System deployment includes the installation, commissioning, acceptance, and handover of the system, as well as the provision of the necessary training, support, and documentation to ensure a smooth and successful system adoption and operation. The main steps in the system deployment process include: Plan the system deployment activities, milestones, and resources, considering the project schedule, budget, and constraints. Coordinate the logistics, transportation, and storage of the system elements, materials, and equipment, to ensure their timely and secure delivery to the deployment site. Install and configure the system at the deployment site, following the installation instructions, safety guidelines, and environmental requirements. 12  System Deployment Perform system commissioning and acceptance tests, to verify that the system is functioning as intended and meets the user and stakeholder expectations. Train and support the users and operators, to facilitate their understanding, proficiency, and confidence in using and maintaining the system. Hand over the system to the owner or the customer, along with the necessary documentation, warranties, and licenses, to enable the system's operation, maintenance, and upgrade. 13  System Operation System operation is the process of managing, monitoring, and controlling the system's performance, availability, and quality during its lifecycle, to ensure that it continues to meet the user and stakeholder needs and expectations. System operation involves the execution of the system's functions and services, the maintenance and repair of the system's components, and the adaptation and improvement of the system's capabilities and resilience in response to the changes in the requirements, environment, or technology. The main steps in the system operation process include: Define and implement the system's operating procedures, policies, and standards, to ensure the system's safety, security, and compliance with the applicable regulations and guidelines. Monitor and measure the system's performance, availability, and quality, using various indicators, metrics, and tools, to detect and diagnose potential issues, trends, or deviations. Maintain and repair the system's components, as needed, to prevent and correct failures, wear, and obsolescence, and to extend the system's life and reliability. 14  System Operation Conduct system audits, assessments, and reviews, to evaluate the system's effectiveness, efficiency, and satisfaction, and to identify areas for improvement or innovation. Update and enhance the system's capabilities, features, and interfaces, based on the user feedback, lessons learned, and emerging technologies, to maintain the system's relevance, competitiveness, and value. Plan and execute the system's decommissioning, disposal, or retirement, at the end of its life or usefulness, to minimize the environmental, social, and economic impacts, and to capture the knowledge and experience for future systems and projects. 15  Sample Problems Problem 1: Explain in your own words the difference between systems engineering and systems integration. Problem 2: Imagine you were hired as a systems engineer for a city planning project. The project involves multiple subsystems such as transportation, utilities (water, electricity, sewage), communication infrastructure, public safety, etc. Your work is to ensure that all these subsystems are efficiently integrated and managed to result in a functional and sustainable city. Describe how you would solve this problem using systems engineering principles. Problem 3: Imagine you are developing a new global positioning system (GPS) for cars. Describe how you would apply the principles of systems engineering in this context. 16  Model Based Systems Engineering (MBSE) ❑ Definition: MBSE is the formalized application of modeling in systems engineering to support system requirements, design, analysis, verification, and validation activities from the conceptual design phase through development and later life cycle phases. ❑ What is modelling? In the context of systems engineering, modelling is the process of creating abstract representations of a system to understand, explore, explain, and predict its behaviour. These models are often mathematical or computational and can represent both physical systems (like machinery or networks) and conceptual systems (like information flows or organizational structures). ❑ MBSE serves several purposes Design Support: Models help engineers design systems by allowing them to simulate and analyze how different components interact and perform within the system. This helps in optimizing design decisions before physical implementation. 17  Purpose of Model Based Systems Engineering ❑ Decision Making: By exploring different scenarios and outcomes through models, systems engineers can make informed decisions about trade-offs and strategies, minimizing risks and maximizing efficiency. ❑ System Analysis: Models allow engineers to analyze the performance, reliability, and other key attributes of systems under various conditions, supporting continuous improvement and innovation. ❑ Verification and Validation: Through modeling, systems can be tested and validated against the intended requirements and performance criteria, ensuring that they meet all specifications before full-scale production or deployment. ❑ Communication: Models provide a visual and quantitative way to communicate complex system interactions and dependencies to stakeholders, facilitating better understanding and collaboration. 18  Traditional Systems Engineering vs. MBSE ❑ Traditional Systems Engineering is a document-centric approach that relies heavily on manual processes and sequential development, using extensive written documentation to manage system specifications. Model-Based Systems Engineering (MBSE), in contrast, utilizes formalized models and integrated software tools to automate and streamline the entire system lifecycle, enhancing collaboration, efficiency, and adaptability. 19  Major Benefits of MBSE ❑ Enhanced Communications: MBSE fosters improved communication across the development team and other stakeholders by providing a shared, clear, and visual understanding of system requirements, design, and operational concepts. ❑ Shared Understanding: It promotes a common, comprehensive understanding of the system across the entire team, which helps in aligning objectives and expectations from the start of the project through to its completion. ❑ Integration of Multiple Perspectives: MBSE allows for the integration of multiple perspectives of a system into a coherent model, ensuring that all aspects such as structure, behavior, and requirements are interconnected and consistently represented. ❑ Reduced Development Risk: By allowing ongoing requirements validation and design verification, MBSE helps in identifying potential issues early in the development cycle, thus reducing risks associated with the system development. 20  Major Benefits of MBSE ❑ Improved Quality: The approach provides a mechanism for more complete, unambiguous, and verifiable requirements, which in turn leads to enhanced design integrity and overall system quality. ❑ Increased Productivity: MBSE can lead to increased productivity through faster and more comprehensive impact analysis of requirements and design changes. It also facilitates more effective exploration of trade-offs (trade-space analysis) and supports the reuse of existing models. ❑ Automated Documentation: MBSE can automate the generation of documentation, which reduces errors and saves time during integration and testing phases. ❑ Lifecycle Support: The models created using MBSE can support various lifecycle activities such as operator training, system maintenance, and diagnostics. ❑ Enhanced Knowledge Transfer: MBSE helps in efficiently capturing and maintaining domain knowledge in a standardized form, which can be easily accessed, analyzed, and updated, 21 facilitating knowledge transfer across the organization.  Core Principles of MBSE ❑ Integration Through Models: Integrates all design and development aspects through consistent and comprehensive modeling. ❑ Model Utilization: Utilizes models for verification and validation processes. ❑ Traceability Maintenance: Maintains traceability throughout the entire system lifecycle, enhancing clarity and control. 22  MBSE Tools and Languages ❑ SysML (System Modelling Language): SysML is one of the key modeling languages used in MBSE. It supports specification, analysis, design, verification, and validation of a broad range of systems and systems-of-systems. ❑ UML (Unified Modeling Language): Another modeling language used extensively in software development. UML helps visualize, specify, construct, and document the artifacts of software systems. ❑ Comparison of SysML and UML Purpose and Focus: UML focuses more narrowly on software systems, making it less suitable for modelling hardware or system interactions at a higher abstraction level. SysML, an extension of UML, broadens the scope to include a wider range of systems elements, which is essential in systems engineering. Wider Usage of SysML in Systems Engineering: SysML's broader capabilities for modelling complex systems, including both software and hardware components, make it more applicable and widely used in systems engineering compared to UML. 23