Systems Engineering Lecture 3 - Conceptual Design

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Questions and Answers

What is the primary focus of system planning in systems engineering?

Establishing an overall plan for successful system design (correct)

Developing a complete set of design characteristics

Defining system requirements and needs

Understanding component interactions

Which statement best describes system architecting?

It involves the development of a detailed project timeline.

It focuses on defining specific software requirements.

It creates a conceptual model to outline system structure and behavior. (correct)

It emphasizes the implementation of hardware components.

What is the main emphasis of the system design process?

Planning for future operational phases

Conducting requirement analyses

Understanding user needs and feedback

Defining system components and their interfaces (correct)

What critical aspect does requirement analysis address in systems engineering?

Identifying and defining user needs and system requirements Signup and view all the answers

Why is conceptual design important in systems engineering?

It helps visualize the overall functionality of the system. Signup and view all the answers

What is the purpose of systems engineering process inputs (SEP)?

To understand project goals and constraints Signup and view all the answers

Which model is NOT commonly recognized in systems engineering processes?

Static analysis model Signup and view all the answers

Which of the following is a major input to the systems engineering process?

Customer's actual needs and requirements Signup and view all the answers

What approach helps in identifying customer requirements during the systems engineering process?

Using functional flow block diagrams Signup and view all the answers

Why is it important to understand the problem thoroughly before advancing in the design process?

To establish a pool of design alternatives Signup and view all the answers

What aspect is essential for the conceptual system design stage?

Systems engineering process inputs (SEP) Signup and view all the answers

Which of the following questions would be least helpful in identifying a customer's actual needs?

What are potential competitors doing? Signup and view all the answers

How does the systems engineer typically adapt the systems engineering process?

By modifying the process to meet specific project needs Signup and view all the answers

What does the system engineering management plan primarily describe?

The overall management approach to system activities. Signup and view all the answers

Why is feasibility analysis conducted in system design?

To identify feasible alternatives for a need. Signup and view all the answers

Which of the following best describes system design?

Defining characteristics of components and their interfaces. Signup and view all the answers

Operational requirements in system engineering include which of the following?

Functional characteristics necessary for execution. Signup and view all the answers

What is NOT part of the technical and performance characteristics of a system?

Market analysis. Signup and view all the answers

Which of the following describes the purpose of system specifications?

To outline the functional requirements of the system. Signup and view all the answers

Which activity is an example of a managerial process in system engineering?

Tracking project schedules. Signup and view all the answers

What is meant by subsystem allocation in system engineering?

Determining the distribution of functions among subsystems. Signup and view all the answers

Study Notes

Systems Engineering (ISAN3070) - Lecture Notes

Course instructors: Binod Timilsina and Inês Peixoto
Course code: ISAN3070
Lecture 3: Conceptual System Design

Learning Objectives

Definition of needs and requirements
Requirement analysis
Conceptual design
Process of conceptual design
Importance of conceptual design in systems engineering

Key Terms

System planning: Development of a comprehensive plan for successful system design, focusing on the management of the design process.
System architecting: Creation of a conceptual model defining the structure and behavior of a proposed system. Focuses on understanding structure and purpose, and how different components interact with each other and other systems.
System design: Process of defining system components and elements (e.g., architecture, models) and their interfaces. Focuses on implementation and creating design characteristics that prepare the system for implementation.

Key Terms, Example

System planning: Develops a plan for completing the system engineering project from need identification to its decommissioning. System architecting comprises defining the concept, decomposing the system, mapping form to function, and defining key operational parameters. System design focuses on selecting operating parameters.
Examples of conceptual diagrams are provided depicting a smart parking device and an order-tracking system for a manufacturing company. A weighing machine design is also presented illustrating diverse design approaches, emphasizing cost, accuracy, and movement.

Conceptual Design: What is It?

Conceptual designs provide a clear picture of the system (i.e., architecture, diagrams, sketches, models).
They help understand the system's appearance, function, and how it serves user needs and requirements.
Conceptual designs allow commitment to specified functions, form, cost, and development schedule.
It's important to distinguish between customer needs/requirements and system requirements. Developing clear system requirements translates customer needs into actionable specifics.

Customer's Needs and Requirements Vs System's Requirements

Customer's needs and requirements: Descriptions from a customer perspective, typically using natural language without technical details, focusing on user environment and application domain.
System requirements: Precise and complete specifications with technical detail. They follow the definition of customer needs and requirements.

Conceptual Design, Example 1 & 2

Examples of conceptual diagrams are provided, such as a smart parking device and an order-tracking system.

Conceptual Design, Example 3

Three examples of a weighing machine conceptual design, highlighting variations in design objectives (low-cost, minimal displacement, and high accuracy), with cost and accuracy figures.

Conceptual Design, Example 4

Examples of conceptual diagrams are provided to conceptualize a modern passenger jet and an iPhone

Exercise: Conceptual Design

A set of exercises are provided to help students practice conceptual design for various scenarios (new supplier, student feedback system, unarmed aerial vehicle, self-driving car, high-speed camera, and a student-generated idea).

Principles of Conceptual Design, Mechatronic Systems

Key characteristics of systems in dynamic environments include agility and autonomy, with a focus on adapting to and anticipating change.
Effective systems should be designed as networks of autonomous units rather than hierarchies.
System design decisions should involve negotiation among constituent units, increasing overall system value.

Process of Conceptual Design

A detailed model and flow are described encompassing problem definition, advanced system planning and architecting, prioritizing technical performance measures (TPMs), and the functional analysis and allocation to subsystems and components. Analysis of factors, system characteristics, and design needs are emphasized.

Problem Definition & Need Identification

Defining the gap between "as-is" and "to-be" states, focusing on real deficiencies and prioritizing needs.
Identifying customer requirements and constraints, translating these into detailed system requirements.

Problem Definition

Needs and requirements define characteristics the system must have.
Determining actual needs and requirements are important inputs to systems engineering process. Steps are described for performing need identification.

Systems engineering process inputs (SEP)

Customer's actual needs and limitations.
Project constraints and limitations.
Functional requirements.
Performance requirements.
Design requirements.
Derived requirements.
Allocated requirements.

Need Identification, Closer Look

Methods for identifying customer needs and requirements through inquiries focusing on the system's functional descriptions, primary and secondary functions, alternative solutions, and timing constraints.

Who are the Customers?

Customers are people who execute the primary functions of systems engineering, especially the "key customer" who defines system requirements
Other entities like investors and regulatory bodies are included.

Basic Questions to Operational Requirements

Questions to help define operational requirements, covering aspects like operational distribution, mission objectives, parameters, utilization environments, effectiveness, efficiency, and operational life cycle. Operational environments are also included.

User Defined Vs System Engineer Defined Concepts

Examples of user-defined and system engineer-defined specifications for a weighing machine.

Examples of Key Requirements in Systems Engineering

Functional requirements: Define the behavior and operation of a system (inputs -> processing -> outputs).
Non-functional requirements: Increase reliability and quality. This includes legal constraints or security features.
Performance requirements: Specify performance metrics, like response speed.
Technical requirements: Detail specifications related to technology use, components, and build specifications.
Operational requirements: Describes operating environment conditions.
System specifications: Define system operation and performance requirements.

Requirement Analysis

An iterative process for identifying requirements and their levels. Identifying top-level requirements, followed by subsystem levels then component levels.

Characteristics of Good Requirements

Requirements should be achievable, verifiable, unambiguous, complete, and consistent, focusing on defining needs ("what and why" not "how").

Models for Elicitation of Customer Needs and Requirements

Overview of four basic models: scenario-based, class-based, behavioral-based, and flow-based.

Advanced System Planning and Architecting

System planning establishes a plan for successful system design.
System architecting creates a conceptual model defining the system's structure and behavior.
Both tasks start once problem definition and need identification are complete

Development of Technical Requirements

Technical requirements describe characteristics for system mission execution like performance, reliability, and availability, and their development considerations.

Development of System Engineering Programme Requirements

Developing system engineering designs and answering questions about how the system works and its required properties.

Advanced System Planning and Architecting - Summary

Diagram summarizing the process with relationships between conceptual design, preliminary design, product specifications, and system plan development.

System Design and Feasibility Analysis

Process of examining whether detailed system design is feasible.
Strategies to define operational feasibility include determining alternative solutions, understanding lifecycle cost and design characteristics, identifying design approaches, and evaluating alternatives.

Identifying System Operational Requirements

Operational requirements relate to a system's effectiveness in performance-based tasks, including reliability, availability, and maintenance. Operational requirements are developed based on identified needs and chosen technology. Examples clarifying requirements are given

Operational Requirements, Example

Detailed example of operational requirements (traffic, vehicles, operation time, quality of materials, maintenance time.) for a bridge.

Factors Influencing Operational Requirements

Explains factors affecting operational requirements, including mission definition, performance parameters, operational deployment, operational life cycle, utilization requirements, effectiveness of factors, and environmental considerations.

System Maintenance and Support

Emphasizes the planning and analysis of maintenance and support activities for a system throughout its lifecycle.
Importance of early planning during conceptual design.
Levels of maintenance (organizational, intermediate, manufacturer)
Key components like repair policies, organizational responsibilities, and maintenance support elements, as well as effectiveness requirements and environmental factors

Identifying and Prioritizing TPMs

Prioritization and hierarchy of technical performance measures (TPMs), using quantitative values to define operational outcomes like design life, reliability, producibility, and maintainability. TPMs are derived from design dependent parameters (DDPs).

TPMs Hierarchy

Prioritization of technical performance measures involves evaluating various aspects (e.g., operational ability, economic viability, environmental effects). Using quantitative data or criteria, prioritization enables making trade-offs during design by focusing on critical performance measures and factors.

TPMs Hierarchy: Quality Function Deployment (QFD)

QFD facilitates the translating of customer needs into technical solutions and focuses on the relationship between the two.
Steps of QFD are illustrated employing matrices like the House of Quality and how needs are prioritized.

Functional Analysis and Requirements Allocation to Subsytems and Components

How to translate requirements into detailed design criteria, as well as identify resources for system operation, including reliability, maintainability, and supportability.

Functional Flow Block Diagram

Block diagrams defining system functions and illustrating their interrelationships.
Use of diagrams to break down top-level functionality into sub-level functions

Functional Allocation

The process for confirming whether a particular function can be completed within resource constraints. Optimizing function allocation to reduce resource requirements and avoid redundant tasks across design units.

The System Architecture

Formal structure for describing the system’s organization in terms of components, interconnections, and relationships. It clarifies how different system elements interact from problem specification to proposed solution.

System Trade-Off Analysis

Method for selecting the optimal design alternative based on multiple factors like commercially available components, manufacturing processes, resource costs, logistics, and maintenance. Trade-off analysis helps compare alternative system solutions against established criteria.

Concept Generation Vs Concept Selection

Tools and techniques for generating various design concepts include system architecture, function-to-form mapping, logical decomposition, brainstorming sessions, and mind mapping strategies. Concept selection aids in deciding among the generated options to identify the best option for the given use case.

System Specification

System specifications (Type-A) in conceptual design represent the top-level requirements. They should specify product, process, technical and performance characteristics, operation, maintenance, support, and function description. Subsystem allocations are also described.

System Specification, example of Level 0

Detailed examples of system specifications (e.g., passenger car, elevator) illustrating the format and content of level-0 system specifications.

Conceptual Design Review

Process for formally reviewing system-level requirements, maintenance concepts, TPMs, functional analysis, and allocations. Main goal is identifying the best option for system design.

Exercises: Conceptual Design

Exercises to help students practice developing conceptual designs in diverse scenarios. Diagrams and sketches are important tools in conceptual design. A critical review of assumed ideas should also be performed.

Assignment Three (Voluntary)

Questions regarding lecture understanding, relevance of conceptual design in systems engineering, and definitions related to technical performance measures, operational/functional requirements, performance requirements, and system specifications.

Any Questions, Comments, or Concerns?

Open forum for questions, comments, and concerns related to the lecture.

Sources

List of scholarly works referenced in lectures including authors, titles, and publication details

End of Notes

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Description

This quiz covers Lecture 3 of the Systems Engineering course ISAN3070, focusing on the conceptual design process. Learn about defining needs, requirement analysis, and the importance of conceptual design in systems engineering. Test your understanding of system planning, architecting, and design.