# Presentation: 103222

## Systems Engineering

***Goddard's GPR Guideline, Mission Concept Studies, and Support Tools***

*John Azzolini*
- Systems Engineering Services and Advanced Concepts Branch
- September 2005

## Agenda

- A Brief Overview Of GPR 7120.5A Concepts
- An Examination Of The Pre-phase A Concept Study To Illustrate The Guidelines
- A Demonstration Of A Systems Engineering Validation Support Tool

- GSFC Systems Engineering Seminar - 9/13/05

## Overview of GPR 7120.5A

- What is the GPR?
- A practical definition of _**what**_ should be done as a part of good systems engineering practice
- Based on the NASA Systems Engineering Handbook SP-6105
- Incorporates principles of industry systems engineering standards
- Why do we have it?
- Correct deficiencies in the execution of systems engineering. (Many of the root causes of Aerospace Industry failures were traced to poor systems engineering)
- Describe what constitutes good systems engineering
- Improve uniformity of systems engineering in completeness and quality
- How can it be useful?
- Serves as a set of reminders for what should be considered
- Provides guidance for establishing a project unique systems engineering plan
- Provide common understanding and expectations within the Goddard systems engineering community

- GSFC Systems Engineering Seminar - 9/13/05

## Overview of GPR 7120.5A

**Principles**
- Encourage a Team Approach
- Cover full mission life-cycle
- Define the _**whats**_
- Show product maturity over life-cycle
- Stress Validation
- Keep good practices of the past

- GSFC Systems Engineering Seminar - 9/13/05

## Overview of GPR 7120.5A

**Document Contents**
- Preface – *Purpose, Applicability, Authority, References, Cancellation, Safety, Training, Records, Metrics, Definitions*
- Roles and Responsibilities
- Communications
- Key Systems Engineering Functions
- Configuration Management and Documentation
- Systems Engineering Management Plan
- App A - Systems Engineering Requirements
- App B - System Engineering Management Plan Outline
- App C - Tailoring Guidelines

- GSFC Systems Engineering Seminar - 9/13/05

## Roles And Responsibilities

Project or study manager teams with Mission Systems Engineer

Mission Systems Engineer coordinates and facilitates team

SEMP describes details

- Project or study manager teams with Mission Systems Engineer
- Mission Systems Engineer coordinates and facilitates team
- SEMP describes details

***Overview of GPR 7120.5A***

- GSFC Systems Engineering Seminar - 9/13/05

## Overview of GPR 7120.5A

- GSFC Systems Engineering Seminar - 9/13/05

## Overview of GPR 7120.5A

***Overview of GPR 7120.5A***

**Communications**
- Systems Engineering is a Team Activity
- The Mission System Engineer facilitates and coordinates team effort
- Solutions converge when _*decisions*_ are made
- Validation is the job of all team members

- GSFC Systems Engineering Seminar - 9/13/05

## Overview of GPR 7120.5A

**Key Systems Engineering Functions**
- Understanding the Objectives
- Operations Concept Development
- Architecture and Design Development
- Requirements Identification and Management
- Validation and Verification
- Interfaces and ICDs
- Mission Environments
- Technical Resource Budget Tracking
- Risk Management
- System Milestone Reviews

***The organization of information, to understand our goals, ...***

***... ******and to systematically achieve them .***

- GSFC Systems Engineering Seminar - 9/13/05

## Overview of GPR 7120.5A

**Configuration Management and Documentation**
- Identify information products which must be “configured”
- Use project CM system to maintain
- Single point of configuration
- Change control at the appropriate time

***Maintaining information which accurately reflects our decisions ...***

***... ******to assure integrated success .***

- GSFC Systems Engineering Seminar - 9/13/05

## Overview of GPR 7120.5A

**Systems Engineering Management Plan**
- What, who, when, where, how
- An active plan, it is updated and used to plan efforts
- Products defined
- Tasks defined
- Schedule maintained
- Costs maintained

***“******Plans are nothing - ...***

***... ******planning is everything” – *****Dwight Eisenhower*****.***

- GSFC Systems Engineering Seminar - 9/13/05

## Slide 12

- GSFC Systems Engineering Seminar - 9/13/05

## Mission Concept Study

- Back to the SE functions
- Understanding the Objectives
- Operations Concept Development
- Architecture and Design Development
- Requirements Identification and Management
- Validation and Verification
- Interfaces and ICDs
- Mission Environments
- Technical Resource Budget Tracking
- Risk Management
- System Milestone Reviews
- What is known?  What needs to be known?
- Let’s start at the very beginning

- GSFC Systems Engineering Seminar - 9/13/05

## Mission Concept Study

***Mission Concept Study***

**Mission Objectives**
***Mission Needs*** is a better term

***“******All the worst mistakes ...***

***... ******are made the first day” – *****Anon.**

- GSFC Systems Engineering Seminar - 9/13/05

## Mission Concept Study

**Mission Needs for Other NASA Mission Types**

- GSFC Systems Engineering Seminar - 9/13/05

## Mission Concept Study

**Design Specification and Validation Flows**

- GSFC Systems Engineering Seminar - 9/13/05

## Mission Concept Study

**Payload Concept**

***Mission Design ...***

***... ******depends on payload design*****.**

- GSFC Systems Engineering Seminar - 9/13/05

## Mission Concept Study

**Mission Design**

***Partitioning of functionality ...***

***... ******between space and ground*** ***is made here*****.**

- GSFC Systems Engineering Seminar - 9/13/05

## Mission Concept Study

***And now  ...***

***... ******system design can proceed.***

**System Design**

**Instrument Accommodation Requirements**

**Mission System Requirements**

**Mission Operations Concept**

**Spacecraft Design**
**Ground System Design**
**Launch Accommodations**

**Mission Architecture**

- GSFC Systems Engineering Seminar - 9/13/05

## Mission Concept Study

*Assuring that the design is correct (“Did we build the right system?”)*
- Validation of mission needs flow-down (“flow of authority”)  (necessary)
- Validation of design compliance to needs (sufficient)
- Functionality
- Performance Analysis
*Verification -** *
*Assuring that the implementation is correct (“Did we build the system right?”)*
- Testing, analysis, and inspection
- Verification of function and performance
- Verification of implementation
- Verification of operations
- Note:  *Many people (erroneously, in my opinion) call end-item operational verification – “Validation” – Pshaw!*

***Mission Concept Study***

**Verification and Validation**

***A  continuing validation of products ...***

***... ******keeps the team coordinated.***

- GSFC Systems Engineering Seminar - 9/13/05

## Mission Concept Study

**Mission Needs**

***Mission Concept Study***

***Putting it all together ...***

***... ******for a complete validation of design.***

**Mission Design**

**System Design**

- GSFC Systems Engineering Seminar - 9/13/05

## Mission Concept Study

***Mission Concept Study***

**Interface Requirements and ICDs**

***... ******allow decoupling of implementation efforts.***

**Interface Requirements**
- Functional
- Performance
- Standards Compliance
**Interface Control Documents**
- Function
- Form
- Specifications

**Properties Covered**
- Mechanical
- Electrical
- Thermal
- Power
- Ground
- ...

- GSFC Systems Engineering Seminar - 9/13/05

## Mission Concept Study

- Launch Environment
- GEVS
- Mechanical – Sine, Sine Sweep, Acoustic
- Electrical - EMI, EMC
- Shock
- External RF

- 	External Space Environment
- Atomic Oxygen
- Radiation TID
- Radiation SEE
- Thermal Cycling
- Power Cycling
- 	Internal Environment
- Grounding
- Noise
- Power Surges

**Mission Environments**

***Determine mission environments early  ...***

***... ******and apply uniformly.***

- GSFC Systems Engineering Seminar - 9/13/05

## Mission Concept Study

**Mission Technical Resources**
- Mass – Affects launch margin, ACS, propellant
- Power – Affects mass, thermal dissipation
- Thermal – Affects Alignment, Life, calibration
- Attitude – Affects measurement resolution, image smearing
- Position – Affects orbit dependent aspect knowledge
- Data – Affects bandwidth, link margin, storage
- RF – Affects power, mass
*Essentially all the things where margins are defined*

***“******Everything depends on  ...***

***... ******everything” – old systems engineering adage.***

- GSFC Systems Engineering Seminar - 9/13/05

## Mission Concept Study

**Mission Risks**
- Safety Risks
- Hazard analyses are the prime method to identify safety risks
- Project management should understand and manage safety risks
- Performance Risks
- FMEA, FTA, RBD and PRA are good tools here
- Sound design practices, simple robust designs, and adequate peer review
- High to low risks often on a logarithmic scale
- Project management should understand and manage performance risks
- Programmatic Risks
- Schedule, Cost
- Classical FMEA, FTA, RBD do not apply here,
- Communication and continuous assessment of progress
- High to low risks often on a linear scale
- Element lead and/or project management has responsibility for managing programmatic risks

***Mission risks ...***

***... ******are of three distinct types.***

- GSFC Systems Engineering Seminar - 9/13/05

## Mission Concept Study

**Product Maturity and Reviews**

- GSFC Systems Engineering Seminar - 9/13/05

## A Systems EngineeringValidation Support Tool

- Caveat:  A fool with a tool is still a fool

- GSFC Systems Engineering Seminar - 9/13/05

## In closing

***In closing***

- GSFC Systems Engineering Seminar - 9/13/05