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Space Systems Engineering: Introduction Module
Introduction Module:
What is Systems Engineering?
Space Systems Engineering, version 1.
Space Systems Engineering: Introduction Module 2
Module Purpose: What is Systems Engineering?
Provide some common definitions of systems
engineering in the context of space project
development.
Motivate the need for systems engineering and
demonstrate the consequences of poor systems
engineering.
Describe how systems engineering adds value to
the development of large projects.
Develop some common systems engineering
process models and show how they are related.
Space Systems Engineering: Introduction Module 3
What is Systems Engineering?
Systems engineering is a robust approach to the design, creation, and operation of systems. The approach consists of:
- identification and quantification of system goals
- creation of alternative system design concepts
- performance of design trades
- selection and implementation of the best design
- verification that the design is properly built and integrated, and
- assessment of how well the system meets the goals This approach is iterative, with several increases in the resolution of the system baselines (which contain requirements, design details, verification plans and cost and performance estimates). Ares 1 Space Systems Engineering: Introduction Module 4
- Systems of pieces built by different subsystem groups did not perform system functions
- Often broke at the interfaces
- Problems emerged and desired properties did not when subsystems designed independently were integrated
- Managers and chief engineers tended to pay attention to the areas in which they were skilled
- Developed systems were not usable
- Cost overruns, schedule delays, performance problems
Original Reasons for Systems Engineering
Photo from Dec 1999 Civil Engineering magazine Vasa, Sweden, 1628
Space Systems Engineering: Introduction Module 7 Systems Engineering is The Response to Trends In The Design and Development of New Space Systems
New space systems are more likely to have:
Technology development A variety of subsystem technical maturities Consider and reuse existing designs Consider and incorporate COTS subsystems Mandated implementations or subsystem vendors Greater dependence on system models for design decisions More stakeholders, institutional partners, constraints and ambiguity More customer oversight and non-advocate review „System-of-systems‟ requirements More people - project sizes are growing Physically distributed design teams Space Systems Engineering: Introduction Module 8
NASA, DOD and Industry Call For
More and Better Systems Engineers
All of the factors identified by NASA that contributed to program
failure and significant cost overrun are systems engineering
factors , e.g.,
Inadequate requirements management
Poor systems engineering processes
Inadequate heritage design analyses in early phases
Inadequate systems-level risk management
Reference: NASA, Office of Program Analysis and Evaluation, Systems Engineering and Institutional Transitions Study, April 5, 2006. Reproduced in National Academies book - Building a Better NASA Workforce: Meeting the Workforce Needs for the National Vision for Space Exploration.
Space Systems Engineering: Introduction Module 9
Systems Engineering is
Built on the Lessons of the Past
Systems engineering is a relatively new engineering
discipline that is rapidly growing as systems get
larger and more complex.
Most of the foundations of systems engineering are
built on the lessons of past projects.
Recurring mission success is codified in techniques
and guidelines (e.g., the NASA Systems Engineering
Handbook).
Since mission failures are each unique, their lessons
retain their identity.
NASA Lessons Learned Resources: http://www.appel.nasa.gov/ask/archives/lessons.php http://pbma.nasa.gov/lessonslearned_main_cid_ http://ildp1.nasa.gov/offices/oce/llis/home/ http://klabs.org/DEI/lessons_learned/ Space Systems Engineering: Introduction Module 10 Declining Systems Engineering Expertise Contributes to a Spectacular Satellite Failure Future Imagery Architecture - FIA - a $5 billion (award) spy satellite system was behind schedule and expected costs to complete were $13 billion over budget. The optical satellite system of FIA was canceled in 2005 after 6 years and spending more than $4 billion. “ … (a) factor was a decline of American expertise in systems engineering, the science and art of managing complex engineering projects to weigh risks, gauge feasibility, test components and ensure that the pieces come together smoothly.” NYT, 11/11/
Space Systems Engineering: Introduction Module 13
- Most of the NASA project data used for the „Werner Gruhl plot‟ are more than 20 years old.
- A study of 40, more recent NASA missions (including those below) showed an average cost growth of 27% and an average schedule growth of 22%.
Cost and Schedule Overruns Continue
to be a Problem on Space Projects
- Discovery
- NEAR
- Lunar Prospector
- Genesis
- Messenger
- Mars Pathfinder
- Stardust
- Contour
- Deep Impact
- Mars Exploration
- MGS
- MCO/MPL
- MER
- MRO
- New Millennium
- DS- 1
- EO- 1
- Explorer
- FAST
- ACE
- TRACE
- SWAS
- WIRE
- FUSE
- IMAGE
- MAP
- HESSI
- GALEX
- SWIFT
- HETE-II
- THEMIS
- Great Observatory Class
- Spitzer
- Gravity Probe B
- Flagship
- EOS-Aqua
- EOS-Aura
- TRMM
- Solar Terrestrial Probe
- TIMED
- STEREO
- Other
- LANDSAT- 7
- SORCE
- ICESAT Space Systems Engineering: Introduction Module 14
Systems Engineering Process Models
Begin with Reductionism
Reductionism, a fundamental technique of systems
engineering, decomposes complex problems into
smaller, easier to solve problems - divide and
conquer is a success strategy.
Systems engineering divides complex development
projects by product and phase.
Decomposing a product creates a hierarchy of
progressively smaller pieces; e.g.,
System, Segment, Element, Subsystem, Assembly, Subassembly, Part
Decomposing the development life of a new project
creates a sequence of defined activities; e.g.,
Need, Specify, Decompose, Design, Integrate, Verify, Operate, Dispose
Space Systems Engineering: Introduction Module 15
A Traditional View of the Systems Engineering
Process Begins with Requirements Analysis
Systems Analysis,
Optimization & Control
Requirements
Analysis
Functional
Allocation
Synthesis/
Design
Requirements Loop Design Loop Verification Loop Understand the requirements and how they affect the way in which the system must function. Identify a feasible solution that functions in a way that meets the requirements Show that the synthesized design meets all requirements Measure progress and effectiveness; assess alternatives; manage configuration, interfaces, data products and program risk Space Systems Engineering: Introduction Module The Systems Engineering ‘Vee’ Model Extends the Traditional View with Explicit Decomposition and Integration Mission Requirements & Priorities System Demonstration & Validation Develop System Requirements & System Architecture Allocate Performance Specs & Build Verification Plan Design Components Integrate System & Verify Performance Specs Component Integration & Verification Verify Component Performance Fabricate, Assemble, Code & Procure Parts
Space Systems Engineering: Introduction Module 19
Good Systems Engineering Requires
Competency in at Least 3 Domains
The NASA systems engineering engine has 17 process activities or systems engineering functions for system design, realization and management. But good systems engineering also requires technical domain and personal attribute competency. This view is captured by the JPL system engineering competency model. Systems Engineering Functions Captured by the 17 process activities Personal Behaviors Domain Specific Technical Knowledge Space Systems Engineering: Introduction Module 20
What is a System?
Simply stated, a system is an integrated composite of people, products, and processes that provide a capability to satisfy a stated need or objectives. What are examples of a system in the aerospace industry? Personnel Facilities Processes Hardware
Space Systems Engineering: Introduction Module 21
Examples of Systems
Space Shuttle Main Engine vs. a collection of parts
Space Shuttle Orbiter with engines and avionics
Space Shuttle Orbiter with solid rocket boosters and
external fuel tank
Space Transportation System (STS) with payload,
launch pad, mission controllers, vehicle assembly
facilities, trainers and simulators, solid rocket booster
rescue ships…
“System of Systems”
STS + International Space Station + TDRSS communication satellites +… Space Systems Engineering: Introduction Module 22
Module Summary: What is Systems Engineering?
Systems engineering is a robust approach to the design, creation, and operation of systems. Systems engineering is a ubiquitous and necessary part of the development of every space project. The function of systems engineering is to guide the engineering of complex systems. Most space projects struggle keeping to their cost and schedule plans. Systems engineering helps reduce these risks. Systems engineering decomposes projects in both the product and time domain, making smaller problems that are easier to solve. System decomposition and subsequent system integration are foundations of the Vee and the NASA systems engineering process models.
Space Systems Engineering: Introduction Module 25
Systems Engineering -
Further Considerations
Systems engineering is a standardized, disciplined
management process for development of system
solutions that provides a constant approach to
system development in an environment of change
and uncertainty.
It also provides for simultaneous product and process
development, as well as a common basis for
communication.
Systems engineering ensures that the correct
technical tasks get done during development
through planning, tracking and coordinating.
Space Systems Engineering: Introduction Module 26
Systems Engineering Process
- The systems engineering process is a top-down,
comprehensive, and iterative problem-solving
process, applied through all stages of development,
that is used to:
- Transform needs and requirements into a set of system product and process descriptions (adding value and more detail with each level of development)
- Generate information for decision makers, and
- Provide input for the next level of development.
- The fundamental systems engineering activities are
- Requirements analysis
- Functional analysis/allocation
- Design synthesis
Space Systems Engineering: Introduction Module 27
- System – The combination of elements that function together to produce the capability required to meet a need. The elements include all hardware, software, equipment, facilities, personnel, processes, and procedures needed for this purpose.
- Systems Engineering – A disciplined approach for the definition, implementation, integration and operation of a system (product or service). The emphasis is on achieving stakeholder functional, physical and operational performance requirements in the intended use environments over its planned life within cost and schedule constraints. Systems engineering includes the engineering processes and technical management processes that consider the interface relationships across all elements of the system, other systems or as a part of a larger system.
- The discipline of systems engineering uses techniques and tools appropriate for use by any engineer with responsibility for designing a system as defined above. That includes subsystems.
- Project Management – The process of planning, applying, and controlling the use of funds, personnel, and physical resources to achieve a specific result Unless specifically noted hereafter we will use “Systems Engineering” to refer to the discipline not the organization.
System, Systems Engineering, and Project Management
Space Systems Engineering: Introduction Module 28
Common Technical Processes to Manage the Technical
Aspect of the Project Life Cycle - NASA Model ( 7123.1A)
The Systems Engineering Engine
