1. From Value to Architecture
Ed Crawley
Aeronautics and Astronautics
Engineering Systems
MIT
Massachusetts Institute of Technology © Ed Crawley 2002
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2. Today’s Topics
•
•
•
•
Objectives
Analysis of architecture
A useful tool
Synthesis of architecture
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3. Learning Objectives
0) Be able to apply the principles, processes and tools of
system architecting to structure and lead the early,
conceptual PDP phase
1) Discuss systems, systems thinking, products, the PDP and
the role of the architect
2) Critique and create architecture, and deliver the deliverables
3) Drive ambiguity out of the upstream process
4) Create the concept
5) Manage the evolution of complexity
6) Critically evaluate current modes of architecture
7) Develop the principles of architecting
This is a course in how to think, not what to think
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4. Process for Critical
Thinking
• Opportunity, challenge, or reference
example identified
• Thinker develops an approach option
• Thinker identifies other options, then
analyzes and criticizes the options vs.
each other and the “developed” approach
• Synthesized, context-appropriate “best”
option is defined
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5. The Role of the Architect
• Defines the boundaries, goals, and
functions
• Creates the Concept
• Allocates functionality and defines
interfaces and abstractions
The architect is not a generalist, but a specialist in
simplifying complexity, resolving ambiguity and
focusing creativity
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6. Four Basic Tensions in
Product/System Development
Benefit
Schedule
Risk
Cost
Value is Benefit at Cost
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7. The Architect Creates Good
Architecture
•
•
•
•
Satisfies customer needs
Incorporates appropriate technology
Meets strategic business goals
Meets or exceeds present and future regulations
Is operable, maintainable, sustainable, reliable
Can be evolved/modified as appropriate
 Can be designed and implemented by envisioned team
 Can be implemented with existing/planned capabilities
AND IS ELEGANT
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8. Deliverables of the Architect
• A clear, complete, consistent and attainable (with 80%90%confidence) set of goals (with emphasis on functional
goals)
• A functional description of the system, with at least two
layers of decomposition
• A concept for the system
• A design for the form of the system, with at least two layers
of decomposition
• A notion of the timing, operator attributes, and the
implementation and operation plans
• A document or process which ensures functional
decomposition is followed, and the form at interfaces is
controlled
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9. Architecture - 6 Views
Principles
Roles &
Definitions
Frameworks
Cases
Themes
Methods &
Tools
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10. Analysis of Architecture
• Form, function and concept - the
architecture
• Upstream influences
• Downstream influences
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11. A Definition
• Architecture
– The embodiment of concept, and the allocation of
physical/informational function (process) to
elements of form (objects) and definition of
structural interfaces among the objects
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Form
Function
• Consists of:
– Function
– Related by Concept
– To Form
Concept
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12. Architecture – Form
Suspension bridge
Cable-stayed bridge
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13. Product Attribute - Function
• Function is the activity, operations, transformations that
create or contribute to performance
• Function is a system attribute, created by the architect
• Function is associated with form, and emerges as form
is assembled
• Function can stated in solution neutral form, as a verb
plus noun, and with a limited syntax
• Externally delivered function is linked to value of a
product
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14. Function is Associate with Form
• Change voltage proportional to current
• Change voltage proportional to charge
• React translation forces
• Carry moment and shear
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15. Concept - the Mapping of
Form to Function
• A system vision which maps form to function and
embodies working principles
• Is in solution-specific vocabulary - it is the solution
• Is created by the architect
• Must allow for the execution of all functions
• Specifies the vector of design parameters, which, when
selected, will establish the design
• Is an abstraction of form, or form is a specification of
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Form
Function
concept
Concept
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16. Dominant Upstream Influence on
Architecture
Regulation
Corporate,
Marketing
Strategy
Need
Competitive
Environment
Goals
Function
Customers
Architecture
Downstream
Strategies,
Competence
Technology
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Form
Concept

17. Product Attribute - Need
• Need is defined as:
– an overall desire or want
– a necessity
– a wish for something which is lacking
• Can also include opportunities to fill unexpressed needs
• Exists in the mind of the beneficiary (outside the
enterprise)
• Expressed often in fuzzy or general (i.e. ambiguous)
terms
• Is interpreted (in part) by the architect
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18. Product Attribute - Goals
• Goal is defined as
– what it accomplishes, its performance
– what the designer hopes to achieve or obtain
• Expressed in the precise terms of Product Development
• Will include goals derived from user Needs (goals from
beneficiaries) i.e. the external functional goals
• Will also include goals from corporate strategy,
regulations, competitive analysis, etc.
• Embodied in a statement of goals (requirements ?)
• Is defined (in part) by the architect
• Exist within, and under the control of the enterprise, and
are traded against other attributes
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19. Framework for Downstream
Influences
Implementation
Function
Architecture
Form
Operations
Concept
Operator
(training, etc.)
Operational sequence
and dynamic behavior
Operational cost
Evolution
Design
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20. Product Attribute - Timing
• When the system operates, the time sequence of
events
• Has two important aspects
– Operational sequence
– Dynamic behavior
• Operations sequence is the total set of steps or
processes that the system undergoes, inclusive
of the primary process for which it is intended
– Including set up, take down, stand alone, contingency
and emergency operations
• Dynamic behavior is the detailed timing of steps,
their sequence, start time, duration, overlap, etc.
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21. Overall Operational Sequence
Store
Waiting in storage
Retrieving,
connecting, powering-up,
setting up, initializing
Get ready
Get set
Loading, preparing
OPERATING
Process only ops.
Executing
Primary Process
Contingency ops.
Go
Emergency ops.
Archiving, unloading
Terminating, disconnecting,
depowering, storing
Inspecting, repairing,
calibrating, updating,
maintaining
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Get unset
Get unready
Fix
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22. Product Attribute - Operator
• Who will use/execute the system
• Necessary for products with human
agents/operators/supervisors [which ones
don’t?]
– most important for human-in-loop (e.g. aircraft,
bicycle)
– important for direct human operation (e.g.
lathe, wheelchair, calculator)
– for other products, can be considered part of
interface/constraints (e.g. human factors
design, industrial design)
• Because of the unique issues of human
performance and safety, it is useful to keep
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separate as an additional attribute 22

23. Product Attribute - Operations Cost
• Operations Cost is a product attribute
• How much it will cost to operate the system
• This is the recurring operational related costs
– Operator and other personnel
– Training
– Maintenance and (nominal) upgrades
– Consumables
– Indirect operating costs (insurance, etc.)
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24. Holistic Framework for Attributes of
the Product and its Operations
global
why
global
what
global
how
global
where
the
the
the
the
system
system
system elements
are
is built accomplishes acts
global
when
global
global
who how much
things
occur
does
them
does
it cost
form
cost
timing operator
opportunity performance process structure dynamics user
expense
need
goals
function
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25. Other Downstream Processes
• The system must be designed, so it must be
architected in such a way that design can
proceed smoothly and efficiently
• The system must be implemented, so it must be
architected for manufacturability, coding,
integration, test, and verification
• The system may evolve and be updated, so it
must be architected with a view towards these
changes - Evolution is really just a recursive pass
through conception, design and implementation
• Each has its own who, what, where, when, ...
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26. Qualitative PDP CDIO
Designing
Conceiving
Design
Goals
Design
Tools
Product
Function
Customer
Corporate
Societal
Needs
Product
Goal
NRE
Costs
Design
Schedule
Process
Methods
Design
Team
Operating
Costs
Product
Timing
Product
Form
Product
Operator
Operating
Impl.
Goals
Implementing
Impl.
Team
Impl.
Tools
Process
Flow
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Impl.
Schedule
Impl.
Costs
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27. Generic PDP
Conceive
Design
Mission Conceptual
Design






Business 
Strategy

Functional 
Strategy

Customer 
Needs

Competitors
Program

plan

Business
case
Goals
Function
Concepts
Regulation
Technology
Platform plan
Supplier plan
Architecture
Commitment
Envision
Preliminary
Design





Implement
Detailed
Design
Requirements 
definition

Model
development
Requirements 
flowdown
Detail
decomposition 
Interface
control
Design
elaboration
Goal
verification
Failure &
contingency
analysis
Validated
design
Element
Creation






Integration,
System Test
Sourcing
Implementation
ramp-up
Element
implementation
Element
testing
Element
refinement







Design
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Operate
Product
integration
Product
testing
System
testing
Refinement
Certification
Market
positioning
Delivery
Life Cycle Evolution
Support







Sales,
Distribution
Operations

Logistics
Customer

support
Maintenance,
repair,
overhaul
Upgrades
Product
improvement
Family
expansion
Retirement
Deploy
Develop
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28. A Tool - Object Process Modeling
• Object: that which has the
potential of stable, unconditional
existence for some positive
duration of time. Objects have
states.
• Form is the sum of objects
• Process: the pattern of
transformation applied to one or
more objects. Processes change
states.
• Function emerges from processes
• All links between objects and
processes have precise
semantics
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Objects
Processes
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29. Process and its Links
• A process is associated with a verb and stateless
• There are a family of about 5 types of links from
process to object
• A process changes the states of its operand(s)
through input and output links
Input link
Output link
• Transporting changes person from here to there.
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30. Summary Object-Process
Links
• P affects O (affectee)
• P yields O (Resultee)
• P consumes O (Consumee)
• P changes O (from state A to B).
• P is handled by O (agent)
• P requires O (Instrument)
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31. Emergence
• A process can be zoomed into sub-processes
• A process emerges from sub-processes
• The process and sub-processes are not linked in
any explicit manner, as the object decomposes
into parts
• Emergence is a powerful feature of systems parts and sub-processes can come together to
cause a process to emerge
• Emergence sometimes yields the anticipated
processes, sometimes does not yield the
anticipated process and sometimes unanticipated
processes
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32. Synthesis of Products
• Parallel processes: Architecture &
Business Case
• Tracing value to architecture
• Ambiguity, creativity and complexity
• Conclusions
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33. Parallel Cycles
• The parallel cycles end when:
- The technical architecture “closes”
- The business case “closes”
• The outputs are products with value to customer and
profits with value to share holder, while providing appropriate
value to society and workforce.
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34. Intent
• An Intent is
– What the purpose is
– What someone hopes to achieve or obtain
• Is always defined by someone
• Useful to create a special symbol for this information
object - supposed to remind you of an arrow - where you
are going
Intent
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35. Function - A Formal
Definition
• Previous Definition: the …transformation…that
contribute to performance…the actions…for
which a thing exists
• Function is intent plus process
Intent
Process
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36. Value - Formal Definitions
Value is delivered when the primary external process(es)
acts on the operand in such a way that the needs of the
beneficiary are satisfied at a desirable cost.
Operand
Beneficiary
Value Delivery
Has
Needs
Interpreting &
Incorporating
Delivering
Primary
Process
Intent on
process
Value Identification
Value Proposition
Product
Object
Value: “how various stakeholders find particular worth, utility, benefit, or
reward in exchange for their respective contributions to the enterprise”
Murman, et al. LEV p178
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37. Product Systems and Value
• Products include
Goods, which are
objects which
implicitly execute a
process
• Products include
Services, which are
processes enabled by
implicit objects
• In both cases, the
value to the primary
beneficiary is in the
process, not the
object
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Products
Goods
Services
Implicit
Process
Implicit
Objects
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38. Whole Product System
• The whole system is the array of objects
necessary to deliver the externally delivered
process to the operand(s).
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39. Value to Intent
• Start by examining the
operand associated
with value
• Next identify the
attribute of the operand
whose change is
associated with value
• Next define the
transformation of the
attribute associated
with value, in solution
neutral form
This will reduce ambiguity and lead you to a value
focused, solution neutral statement of intent on process
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40. Concept
• Concept: a system
vision, which embodies
working principles, a
mapping from function
to form
• Choose from among the
system operating
processing that
specialize to the desired
solution neutral, value
related process
• Specialize the related
generic concept to the
product form
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This is the
exercise of
creativity
Five primary
functions. McGee,
deWeck
Concept
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41. Capturing Intent
• Once the system is modeled
or built, the “attribute
transforming” process and
“concept” object vanish
• The “attribute transforming”
can be captured as an intent
object
• The concept usually remains
implicit, represented by the
operating process and
concept specialization
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42. Decomposition of Function and Form
• Identify form of the
whole product
system
• Zoom the processes
of function
• Decompose the form
of the product object
• Establish the object
process links
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43. Form and Function - Cooler
• The whole product
includes the ice, food,
supporting surface, heat
load, light and operator
• Chilling zooms to the
stated processes (using
process precedence
framework)
• Cooler decomposes to
box and top
• Map objects to processes
to determine objectprocess architecture
Establishing the complexity of the object-process architecture
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44. Structure of Form - Cooler
• Examine the
interactions
implied by
the
decompositio
n of form
Establishing the complexity of the object-object architecture
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45. Form and Function - Refrigerator
• More one to one
correspondence
of objects and
processes
• Note the whole
product
elements
suppressed:
– Food
– Support
structure
– Heat load
– Operator
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46. Structure of Form - Refrigerator
Considerably more
object - object
complexity
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47. So Why Refrigerators and not Coolers?
• Refrigerators have significantly more
complexity than coolers
• Refrigerators have more functions, performance
and robustness than coolers.
Is a principle lurking here?
Principle: underlying and long enduring
fundamentals that are always (or almost
always) valid.
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48. A Principle
Robust Functionality Drives
Essential Complexity
• Essential complexity is that which is essential to
deliver functionality before gratuitous complexity
slips in
• Functionality drives complexity in any given
concept
• But “Functionality” is often defined as a
surrogate for a much broader set of functions
which the product will actually be use for.
• Therefore, it is the (often implicit) robust
functionality which drives essential complexity
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49. Conclusions
• Architecture requires consideration of form and
function, related through concept
• Value derives from function
• Starting with the operand, its transformation
identifies concepts which deliver value
• Concepts elaborate into architectures which have
form-function and structural complexity
• Essential complexity is accepted to deliver robust
functionality
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