1. 1 ME 59700 Spring 2013 Introduction to Systems Engineering Session 3 Dr. Dan C. Surber, ESEP © Copyright 2013

2. 2 Lecture Topics Concept Exploration Types of Requirements Wasson’s SOI construct

3. 3 Concept Exploration CONTEXT Diagram (your SOI related to all others) Concept of Operations & Support (CONOPS) –Missions –timelines System Architecture Elements (SA) –Hardware items –Software items –Technical data –Tools –Support equipment & Special Test Equipment (STE) –Facilities (mfg., testing, assembly, depot) –Training –People Four (4) types of system requirements –Performance -- Interface –Environment -- Design Constraint Product Breakdown Structure (PBS) Technology Readiness Level (1-9) Your System Environ- ments Data Senders Data Receivers Threats

4. 4 SoS, SOI, MS, & SS SoS - Systems that interact with each, but were not all intentionally designed to work together, may exhibit unexpected behaviors upon interaction. Interoperability – the capacity for two or more systems to exchange inputs & outputs across an interface without adversely affecting operational effectiveness and suitability System of Interest (SOI) Mission System (MS) Support System (SS) Mission System performs the functions that yield results that are operationally suitable and effective for the User’s Need. Support System performs the functions that enable the Mission System to complete its operations and execute the mission life cycles defined by the User’s Need.

5. 5 The “Vee” Diagram Concept Development Preliminary Design Detailed Design Build & Test Integration Qualification Testing System Validation Test & Evaluation Master Plan Subsystem Test Plan Product & Component Test Plans Credit to: Forsberg & Moor; Ben Blanchard & Wolter Fabrycky; J.O. Grady

6. 6 Mission Event Timelines Understand the mission events performed by the Mission System –Operational suitability –Operational effectiveness Understand how the Support System prepares the Mission System for its next mission cycle Identify Target Determine Target Range & Speed Establish Target Aim Point Commence Reload Confirm Weapon Guidance Launch Weapon What if the weapon requires man-in-the-loop guidance commands until impact?

7. 7 Example System Context Diagram Concept of Operations & Support 4 Types of System Requirements –Performance –Environmental –Interface –Design Constraint Product Breakdown Structure System Architecture

8. 8 System Context for ISS System Of Interest (SOI) International Space Station Natural Environment Induced Environment Man-made Environment Threat Environment Other Systems Micro meteorites Space Debris A-Sat Weapon ammonia coolant leaks lost tools and parts leaking fuel from robot resupply RF energy from Shuttle radar laser landing/alignment signals UHF comms from ISS comms vacuum of space solar winds & flares hot & cold extremes robotic resupply vehicles NASA TDRSS comm satellites

9. 9 Types of System Requirements PERFORMANCE – station shall remain on orbit for at least 10 years. INTERFACE – station shall interface with US Space shuttle and Russian resupply vessels. ENVIRONMENT – station shall survive micro meteorite impacts without loss of pressurization or power for the life of its time on orbit. DESIGN CONSTRAINT – station shall accommodate 99 percentile males and 1 st percentil females. TECHNICAL PERFORMANCE MEASURES ACQUISITION & TECHNICAL –KEY PERFORMANCE PARAMETERS (KPP) MEASURES OF EFFECTIVENESS (MOE) –MEASURES OF PERFORMANCE (MOP) »DATA ELEMENTS –THRESHOLD CRITERIA –OBJECTIVE CRITERIA Provide a manned station for long term on orbit research operations.

10. 10 Mission Analysis & CONOPS Understand the primary mission(s) of the SOI –Scenarios within each mission profile –Understand the division between MS & SS Construct Mission Even Timelines Use System Context to discover relationships between SOI, MS, SS and external elements –Environments (natural, induced, man-made) –Interfacing systems –Design constraints –THREATS (natural, man-made) Feed Requirements Analysis –Performance -- Environmental –Interface (external) -- Design Constraint Preliminary System Architecture

11. 11 Mission Event Timelines Understand the mission events performed by the Mission System –Operational suitability –Operational effectiveness Understand how the Support System prepares the Mission System for its next mission cycle Orbit the station core Orbit & attach truss with solar panels Orbit air lock module Add on-orbit spares Add science modules & air locks Add remaining truss & solar panels On-orbit assembly of the ISS MS = on-orbit modules SS = space shuttle, robot resupply, ground control

12. 12 Concept of Operations & Support MSN SYS WHO WHAT WHERE WHEN HOW WHY SPT SYS WHO WHAT WHERE WHEN HOW WHY MISSION TYPES LEVELS OF MAINTENANCE TRAINING K S A EXISTING SPEC CODES OBSOLETE SEPC CODES NEW SPEC CODES

13. 13 Further Concept Exploration Functional Analysis & Decomposition –Functional Block Diagrams –Functional Flow Block Diagrams –Architecture Analysis/Block Diagram Allocation of Performance Requirements to lower tier FUNCTIONS Schematic Block Diagram of Concept –Intra-faces & Inter-faces –Allocation of other requirements to SBD elements Product Breakdown Structure System Architecture Block Diagram

14. 14 Product Breakdown Structure Decomposes the system into its configuration item groupings (by function, by supplier, or by template from a standard) Use at least a 3-tier construct –System –Product –Component Most systems have more tiers (5, 7 or 9)

15. 15 PBS Breakdown System of Interest ISS SoS Support System ISS Supt Sys Mission System ISS US Space Shuttle NASA Msn Control Unity ModuleZarya Module 12 other Modules Subsystems Astronaut Tng Facility