Elements of Systems

Engineering (SE)

Presentation to AERO 401

10 February 2015

Harry M Elmendorf

My Background• Four years USAF at The School of Aerospace Medicine

– Manned Orbiting Laboratory (MOL) Research – Long duration human space flight

• Over 40 years in Aerospace and Defense Industry

• Systems Engineer on diverse programs including:

– Skylab RCS and ECS

– Fleet Satellite Communication Satellite (FltSatCom) – Propulsion system

– Viking Lander Biology Experiment (VLBI) – First Mars lander

– MIRACL High Energy Chemical Laser

– Halogen Occultation Experiment (HALOE) – NASA space instrument

– LIDAR In-Space Technology Experiment (LITE) – First space LIDAR

– A-12 Optical Air Data System (OADS) – Stealth aircraft

– Other satellites, rockets and space, air and ground remote sensing systems

• As a long time member of the Aerospace Engineering External Advisory

Board, I have been an advocate for strengthening our Systems

Engineering curriculum.

The Case for Systems Engineering

• SE is the overarching technical discipline in the product life cycle.

• SE is used extensively by the Aerospace and Defense Industry and

U.S. Government agencies as well as most commercial product and

services companies.

• SE has been demonstrated to significantly increase the probability of

mission (product) success – increased efficiency, decreased rework,

decreased cost, optimization of the life cycle.

• Texas A&M Look College of Engineering has recognized the need

and is developing a Masters Degree Program in Systems

Engineering.

What is Systems Engineering?

• One definition derived from the ABET definition of Engineering is:– “The multidisciplinary application of analytical, mathematical and scientific

principles to formulating, selecting and developing a solution that has acceptable risk, satisfies user operational needs and minimizes development and life cycle costs while balancing stakeholder interests.”

• “Systems engineering is a discipline that concentrates on the design and application of the whole (system) as distinct from the parts. It involves looking at a problem in its entirety, taking into account all the facets and all the variables and relating the social to the technical aspect.” (Sy Ramo)

• Simply stated, SE is an engineering discipline that bridges the gap between the acquirer/owner needs or operational requirements and the system developers while addressing stakeholder needs and external influences.

Available References

• International Council on Systems

Engineering – Student membership

available

• NASA Systems Engineering

Handbook

• DoD Systems Engineering Guides

Role of SE

• SE provides the oversight and guidance of the analysis, design and

development of a product (system) throughout the product life cycle

from concept to disposal.

• SE must assure that all aspects of a system are addressed

including:

– Mission performance

– Physical and environmental interfaces – internal and external

– Support needs – personnel, tools, facilities, equipment

– Stakeholder needs

– Social, legal and economic factors

• SE is usually the lead engineer managing the planning, organizing,

implementing and controlling the product life cycle.

Application of SE• SE can (should) be applied to any process where a mission

(functional) need is expected to produce an operational (functional) capability.

• The mission need is provided by the acquirer (customer, owner, user) in terms of a statement of requirements – i.e. RFP, SRD, SOO, SOW, etc.

• Those requirements normally define the user needs in terms of expected performance of the product (or service), schedule, quantities, environments, external system interfaces, terms and conditions, etc.

• The SE (team) must assess those requirements with respect to other influencing needs and derive additional requirements and define methods for verifying they are met in the product design.

Understand the customer needs

The Systems Engineering Process - INCOSE

SE Process• First – understand customer needs (requirements)

• Second – understand user needs (who is user?)

• Third – understand stakeholder needs and external influences

• Fourth – Go back to First and revise requirements with customer

• Derive additional requirements (may be done sooner)

• Flow down requirements to sub-elements

• Develop requirements verification matrix

• Develop design concepts and review – revise requirements

• Perform trade studies

• Develop preliminary design(s) and review

• Select preferred solution, develop, analyze, revise and review

• Continue thru final design, manufacture, integration, test and operation to disposal (life cycle)

The Vee Diagram

NASA SE Process

Systems Engineering Tools

• Work Breakdown Structure (WBS)

• Program Evaluation Review Technique (PERT)

• Gantt Chart

• Logic Network (Precedence)

Project Work Breakdown Structure

Halogen Occultation Experiment (HALOE)

• NASA LaRC science program

to measure ozone content in

the upper atmosphere

• Built by TRW and launched on

UARS in 1991

• Measures ozone and other

trace gasses using the sun’s

energy collected through a

cassegrain telescope using

gas filled absorption cells

PERT Chart for HALOE

Viking Mars Lander Example• Viking Lander Biology Instrument (VLBI) was the primary Mars

Lander Program mission need

• Purpose was to search for life on Mars -

• Initial work at JPL et.al. did not have sufficient management direction and fell short of meeting NASA’s expectations. NASA removed the VLBI program from JPL gave it to LaRC with Martin Marietta and TRW.

• These issues ultimately caused the program costs to rise from $14M to $60M.

• TRW, under contact with Martin Marietta, applied stringent SE to develop the complex instrument and successfully deliver, launch and complete the missions – 2 landings on Mars

• Stringent requirements drove exceptional technology development – The full instrument had to be sterilized prior to delivery and kept that way

– Contained high pressure (6,000 PSI) ultra pure (99.9999%) Helium gas supply –certified by NBS and tested to margin of safety of 1.5

– Had to be evacuated internally to

– Valves and tubing were all miniaturized (7mm ID) (samples)

– All parts required ultra cleaning – new procedures developed

– All internal plumbing had to be compatible with growth nutrients

– All work done in Class 100,000 clean room – gowns, hoods and snoods

– Had to survive launch and landing environments

– Had to function in Mars environment

Viking Mars Lander Example (Cont)

Summary

• Successful Systems Engineering requires understanding what the

customer wants, what they need and what they can afford.

• It requires understanding who all the stakeholders are and what their

needs are.

• It requires understanding all other external and internal interfaces

and influences on the system.

• Finally it requires the ability to bridge the gap between those

requirements and the system development team.

Question?

Manned Orbiting Laboratory (MOL) – 1960’s

Skylab - 1973

Fleet Satellite Communication System - 1978

Mid IR Advanced Chemical Laser (MIRACL) -

1980

LiDAR in Space Technology Experiment -

1987

A-12 Optical Air Data System - 1989