Principles of Engineering System Design

Dr T Asokan [email protected]

Principles of Engineering System Design

Lecture 2 Dr T Asokan

[email protected]

044-2257 4707

Classification of systems Engineering system examples When do we need system engineering System dimensions System design hierarchy System Engineers and their roles T Asokan

T Asokan

System Examples Spacecraft as a System A spacecraft can be considered as a system composed of a variety of subsystems Spacecraft architrcture (the division into subsystems) is fairly well defined The subsystem are in turn composed of smaller subsystems Payload (Communication) •Antenna •Amplification •Modulation/Demodulation •Routing •Encryption/Decryption •Filters •Multiplexers Spacecraft Spacecraft Bus •Attitude determination and control •Command and data handling •Payload processing •Power •Propulsion •Software •Structures •Telemetry tracking and command •Thermal

Space System

A spacecraft is also part of a larger system • Other spacecrafts in the constellation (the space segment) • Space segment + ground segment + launch segment forms an even larger system Launch Segment Space Segment Ground Segment Mission Operations Element

Ford Product Development System

The SAGA Air Defense System

The Atlas Project

•Produced the first ICBM •18,000 scientists and engineers •17 contractors •200 subcontractors •200,000 suppliers •Coordinated by the Ramo Woodridge Corporation

T Asokan

When do you need systems engineering? Air Bag System for Passenger cars - Requirement analysis failure Pathfinder Communications failure: - Interface design failure Ariane 5 Launch Vehicle failure: - System qualification test failure Discussion: GSLV Failure: Is it a system failure or component failure?

When do you require system engineering ?

Characteristics of system whose development, test, and application require the practice of system engineering are:  The system is an engineered product and hence satisfies a specified need  The system consists of diverse components that have intricate relationships with one another and hence is multi-disciplinary and relatively complex  The system uses advanced technologies that are central to the performance of its primary functions Examples: Satellites, aircraft, auto assembly plant, railway reservation system etc.

• Systems Engineering integrates all the disciplines and specialty groups into a team effort forming a structured development process that proceeds from concept to production to operation. • Systems Engineering considers both the business and the technical needs of all customers with the goal of providing a quality product that meets the user needs. Discussion Point 1 : What distinguishes

Systems Engineering

from

Engineering

?

System Dimensions

Technical Dimension: 6 Levels Social Dimension: 6 Levels 0 - Parts or lines of code 1 – Components or major software units 2 – Major subsystems or subassemblies: both hardware and software 3 – The aircraft and/or related systems 4 – The air transportation system or the air defence system 5 – Physical environment of the world 0 – Individuals 1 – Working groups/teams 2 – Organizational units 3 – Single organizations 4 – Extended multi organization enterprises, Including partners and suppliers 5 – Society, nations, communities, etc.

SYSTEM DESIGN HIERARCHY

SYSTEM ENGINEERS

     They design the overall architecture, not components They prioritize the system requirements They decide on the risks to be undertaken They decide on the risk avoidance strategies They decide on how the system performance and system affordability may be achieved  They guide the system development purely on their knowledge of the system  They decide how to tackle unanticipated problems.

KNOWLEDGE DOMAINS OF SYSTEM ENGINEER

Characteristics of Successful System Engineers 1. Enjoy learning new things and solving problems 2. Like challenges 3. Are skeptical of unproven assertions 4. Are open minded to new ideas 5. Have a solid background in science and engineering 6. Have demonstrated technical achievement in a specialty way 7. Are knowledgeable in several engineering areas 8. Pickup new ideas and information quickly 9. Have good interpersonal and communication skills

System Engineers as Problem Solvers



A problem has three components:

   An undesirable initial state A desirable goal state Obstacles that prevent the transformation from undesirable to desirable T Asokan

Characteristics Good Problem Solvers



Intelligence and creativity



Decision making behavior

    Recognizing dependencies Estimating importance and urgency Continuity and flexibility Acceptance of failures T Asokan

Assignment 1 Identify 5 Natural systems and 5 Artificial systems. Decompose one of these systems into technical and human systems and identify the levels of interactions.

Group Work I From the history of industrial disasters, identify one case study for system failure. Make a presentation of the case by highlighting the following factors.

1.System details 2.Failure mode 3.Failure analysis 4.Root cause 5.Proposed solution(s)

System Design Software - CORE •Download software (university edition) from Vitech corporation ( www.vitechcorp.com

) (IIT Madras is a partner in Vitechcorp’s University education programme) •Password: Contact [email protected]

• Install software ( refer installation guide) •Register product •Learn the fundamentals using “guided tour” available in the help.

•Use the software for your assignments and projects.

SUMMARY • A system is a set of interrelated components working together toward a common objective • System engineering has the function of guiding the engineering of a complex system • System engineering is a powerful discipline, requiring: • A multidisciplinary knowledge, integrating diverse system elements • The ability to perform approximate calculations of complex phenomena, thereby providing “sanity checks” • Skeptical positive thinking for prudent risk taking ARE YOU READY ?