CrawleySimmons sdm Oct 06

Towards a Formalism forSystem ArchitectureFrom Value to Architecture: 

Towards a Formalism for System Architecture From Value to Architecture Prof. Ed Crawley and Willard Simmons October 20, 2006

Outline of Today: 

Outline of Today The challenge A bit of theory Architecting for value delivery Architecting for value, a new way

The Challenge: 

The Challenge We conceive, design, implement and operate really complex and sometimes unprecedented systems Are they architected well? Do they meet stakeholder needs? How do we better define interfaces for more reliable integration? How do we adapt to new environments? How do we evaluate the value of commonality?

Architecture: 

Architecture Architecture The embodiment of concept, and the allocation of physical/informational function to elements of form, and definition of interfaces among the elements and with the surrounding context. Consists of: Function Related by Concept To Form Form Function Concept

Architecture – Mechanical: 

Architecture – Mechanical Cable-stayed bridge Suspension Bridge Source - www.bridgepro.com Concept? Function? Form? Interfaces? Context?

Architecture - Communications: 

Architecture - Communications Insert scanned image of cannon camera system Concept? Function? Form? Interfaces? Context?

Are these Good Architectures?: 

Are these Good Architectures? Do these architectures: Respond to stakeholder needs and deliver value? Rely on creative solutions? Provide leverage within one project? Good interface control? Cross project standardization? Architecture is the primary link between benefit and cost! Early = high leverage on an organization’s activities Source of competitive advantage Alignment with the role many of our organizations do in development - architecting is what we do!

Key Questions in Architecture: 

Key Questions in Architecture How can we represent architectures? How can we rigorously search the option space? How can we select an architecture that has desirable value delivery? How can we identify the decisions that lead to the selection of a preferred architecture?

Objects: 

Objects Defined: An object is that which has the potential of stable, unconditional existence for some positive duration of time Can be physical: visible or tangible and stable in form Can be informational: anything that can be apprehended intellectually Objects have states (which can be changed by processes) Objects are linked to nouns Object

The Whole Product System: 

The Whole Product System We usually architect form which is both a product and a system, and which we designate the product/system Often for the product/system to deliver value, it must be joined and supported by other supporting systems Together, the product, plus these other supporting systems, constitute the whole product system. Whole Product System Product/ System Supporting Systems

Operand: 

Operand The product/system almost always operates on an operand It is the change in the state of an operand that is associated with the delivered value of the product system Focus the analysis or synthesis of an architecture on the operand in order to understand the delivery of value Operand Whole Product System Product/ System Supporting Systems

Boundaries: 

Boundaries The product/system is separated from other supporting systems and the operand by a boundary The boundary is vital to the definition of architecture, because it defines: What you architect, eventually deliver and are responsible for What is “fixed” or “constrained” at the boundaries Everything that crosses a boundary must be facilitated by an interface Interfaces tend to be the most stable aspect of an architecture

Product System Questions?: 

Product System Questions? What is the value related operand? What is the product system? What are the supporting systems? What are the interfaces? What is the use context?

Product - Whole Product - Context: 

Product - Whole Product - Context Food Outside Air Inside Air Operator Outlet Floor Refrigerator Whole Refrigerator System Kitchen Etc. Counters Other appliances Cabinets Product/system boundary Whole product system Usage context

Form = Objects + Structure: 

Form = Objects + Structure Object 1 Object 2 Object 3 Defined: The relationship among the elements of form, which we call the objects Can be physical: visible or tangible and stable in form Can be informational: anything that can be apprehended intellectually NB: does not imply contact, but only interrelationship Can represent ‘formal’ relationships: Topological (within, touching) Spatial (aligned with, distant from) Connectivity (bolted to, wired to) Good practice is to specify what a connection or matrix entry means

Processes: 

Processes Defined: A process is the pattern of transformation applied to one or more objects Cannot hold or touch a process - it is fleeting Generally creation, change, or destruction A process relies on at least one object in the pre-process set A process transforms at least one object in the pre-process set A process takes place along a time line A process is associated with a verb Processing

Slide17: 

Process is Associate with Form Change voltage proportional to current Change voltage proportional to charge React translation forces Carry moment and shear Resistor Capacitor Pin Support Beam

Emergence: 

Emergence As elements of form are brought together, new processes emerge Processes do not combine in any “linear” way - it is often difficult or impossible, a priori, to predict the emergent process In design, the expected process function may appear, may fail to appear, or an unintended process may appear It is exactly this property of emergence that gives systems their “power”- definition of ‘system’: A set of interrelated elements that perform a function, whose functionality is greater than the sum of the parts

External Function Produces Benefit: 

External Function Produces Benefit The project/system always executes externally delivered functions = process + operand Transport Oil Power Equipment Support Platform Sort Array It is the external function that delivers benefit, and therefore value, of the project system The form generally is an instrument of delivering benefit, but is not unique to the benefit delivery If a competitor delivers the same function with another object which is superior, they will displace you 610

Semantically Exact Representation with OPM: 

Semantically Exact Representation with OPM Architecture is made up of operands + processes (functions) plus instrument object (form) Examples: Material is transported by ship Oil is transported with a pump Equipment is powered by an electric generating plant Platform is supported by a spar Array is sorted by bublesort routine Processing Instrument Object Operand Function Form 610

Architecting “Up and Down”: 

Architecting “Up and Down” Stakeholder - Needs Value - Intent Concept Architecture Operations Synthetic Process

Needs of Stakeholders: 

Needs of Stakeholders Need is a product attribute 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 or unrecognized needs

Value Identification -Goals on Externally Delivered Process : 

Value Identification - Goals on Externally Delivered Process Next examine the operand associated with value Identify the attribute of the operand whose change is associated with value Define the transformation of the attribute associated with value, in solution neutral form and its attributes Solution neutral transforming Attribute of transforming Beneficial Attribute Operand Other Attribute Beneficiary Need Intent This will lead you to a value focused solution neutral statement of intent on process

Value Identification - Refrigerator: 

Value Identification - Refrigerator Beneficiary = kitchen worker Need “my food rots too fast” Operand = food Value attribute = spoilage rate Transformation = slowing Slowing How much? Spoilage rate Food Kitchen worker Identifying/ Incorporating Value Identification 610

Solution Neutral to Specific Function: 

Solution Neutral to Specific Function Next identify the specific operand (if not the same as the generic operand), and its specific beneficial attribute Then choose a the process part of the concept which specializes the solution neutral process Define attributes of the process Solution neutral transforming Specific system Operating Attribute of operating Attribute of transforming Beneficial Attribute Operand Specific Operand Beneficial Attribute Beneficiary Need Intent Function 610

Concept - Definition: 

Concept - Definition A product or system vision, idea, notion, or mental image which maps Function to Form Embodies principle of operation Includes an abstraction of form Establishes the solution-specific vocabulary - it is the solution Is not a product/system attribute, but a mapping

Concept - Formal Definition: 

Concept - Formal Definition The combination of: The specific system operating process… enabled by the generic form object… specialized as a specific system form. Concept Specific system Operating Specific System form Generic Concept form Solution neutral process Specializes Agent Link

Concepts - Preserving Food: 

Concepts - Preserving Food Solution neutral statement is: ‘preserving food’ Solution specific processes: chilling, freezing, etc. Solution specific form for chilling: refrigerator, cooler, etc. Concept is chilling with a refrigerator Preserving Chilling Refrigerator Chiller Food Cooler Irradiating Freezing ???? ??? Selected Concept

Specific Function to Specific Form: 

Specific system Operating Specific Function to Specific Form Specific System form Attribute of form Generic Concept form Next choose the generic and specific form part of the concept to execute the specific process Define the attributes of the form Solution neutral transforming Attribute of operating Attribute of transforming Beneficial Attribute Operand Specific Operand Beneficial Attribute Beneficiary Need Intent Function Form

Complete Value Template - Refrigerator: 

Complete Value Template - Refrigerator Slowing Chilling Refrigerator 16 ft3 Chiller By 90% Spoilage rate Food Efficiently At 40˚ Kitchen worker Need Intent Function Form 610

Value - A Formal Definition: 

Value - A Formal Definition Value is delivered when the external process(es) acts on the operand in such a way that the needs of the beneficiary are satisfied at a desirable cost. Specific system Operating Specific System form Beneficial Attribute Operand Beneficiary Value Delivery The relation between the beneficiary and the operand in undefined (the beneficiary could be the operand, own the operand, love/hate the operand, etc.) ?? Note that in operations, intent ‘vanishes’ unless recorded 610

Slide32: 

Food Outside Air Conducting, Convecting Inside Air Conducting, Convecting Refrigerating Circulating Sensing, Feeding back Illuminating Refrigerator Cabinet Condenser Fan Opening, closing Grasping, moving Mixing Transferring load Controller Shelves Light Insulated door Operator Power carrying Load carrying Outlet Frame Floor Structurally interfacing Power interfacing Wheels Plug/chord Wiring Refrigerator project/system boundary Evaporator Fan Circulating

Slide33: 

Food Outside Air Conducting, Convecting Inside Air Conducting, Convecting Refrigerating Circulating Sensing, Feeding back Illuminating Refrigerator Cabinet Condenser Fan Opening, closing Grasping, moving Mixing Transferring load Controller Shelves Light Insulated door Operator Power carrying Load carrying Outlet Frame Floor Structurally interfacing Power interfacing Wheels Plug/chord Wiring Refrigerator project/system boundary Evaporator Fan Circulating

Slide34: 

Food Outside Air Conducting, Convecting Inside Air Conducting, Convecting Refrigerating Regulating Illuminating Box Opening, closing Grasping, moving Mixing Transferring load Light Insulated top Operator Powering Load carrying Ice Floor Structurally interfacing Melting Cooler! project/system boundary Circulating Circulating

Our Effort:Systems Architecture Research: 

Our Effort: Systems Architecture Research Mission: Develop formal methods and tools for Systems Architecting. Methodology: Apply these ideas to current projects from Government and Industry. Tools: Object-Process Network (OPN), a computable graphical language for systems architecting.

OPN Project Objectives: 

OPN Project Objectives To improve the thoroughness and efficiency of system architecting, By automating the mechanical tasks in architectural reasoning and model construction, Using an executable meta-language: “Object-Process Network” (OPN). OPN supports architecture evaluation by: Functioning as a declarative language to describe the feasible space of architectures. Functioning as an imperative language to automatically generate large sets of models of feasible system configurations. Functioning as a simulation language to evaluate and sort system concepts using customized metrics.

What is OPN?: 

What is OPN? OPN is a visual and computable meta-language that assists with systems architecting tasks. OPN is used to: Describe and Partition the space of architectural alternatives. Generate and Enumerate the set of instances of feasible system models. Simulate and Order the performance metrics of the generated models. OPN is a network (a directed graph) of objects and processes connected by relationships An OPN model can be created, edited, and executed using the OPN IDE Software

OPN IDE Screenshot: 

OPN IDE Screenshot

OPN Applications (so far): 

OPN Applications (so far) Published Space-related Applications: Retrospective study of the Apollo decision process. Support the Moon/Mars architecture selection for the Draper/MIT CE&R project Evaluation of the Shuttle Derived Heavy Launch Vehicle architectures for Draper/MIT CE&R Project. NASA Value Flow / Policy Network analysis. Study of Decisions in NASA Lunar Lander Project Other Applications Oil Exploration of Sakhalin Island for (Supporting BP) Electronics Pod Selection for Aircraft (support Draper) Proposed Study of Earth Observation Satellites for NASA Goddard

MIT/Draper CE&R Project: 

MIT/Draper CE&R Project Goal: To help NASA identify sustainable system of system architectures for exploration Approach: Define measures of sustainability for design Comprehensively search the architectural space(s) Identify key policy, technology and operational decision points Project the resulting functionality onto the CEV, to determine the robustness of its requirements to further downstream decisions September 15, 2004 – September 14, 2005 Draper / MIT team was one of 11 industry teams for Phase I, one of 2 for Phase II Involved about 50 people from Draper Labs and MIT Holistic Sustainable Mars-Back Modular, Accretive, and Minimal

Exploration Architecture Approach: 

Exploration Architecture Approach

Main Value Flows: 

Main Value Flows

What are the Value Driven Objectives?: 

What are the Value Driven Objectives? Identify stakeholder, their needs and derived objectives Translate objectives into metrics, proximate measure and indicators Proximate indicators drive exploration architecture Auxiliary columns Auxiliary columns

Transportation Architecture Approach: 

Transportation Architecture Approach Requirements and Indicators Requirements Crew size Cargo mass Mars mission duration Metrics Initial mass in Low Earth Orbit (IMLEO) Dry mass of unique elements Overall safety and risk metric (OSRM) Available contingency plans Software development cost Questions Addressed Where should the CEV go? What other vehicles are needed? What propulsion should be used? Should in-situ resources be used? What size of HLLV is needed? Approach – Moon and Mars Generate all feasible Lunar and Mars architectures Analyze architectures Screen architectures Commonality analysis for promising Lunar and Mars architectures Size TMI/TLI stages Select launch vehicle size(s) Constraints and Assumptions Fast-Conjunction Mars Missions Aerocapture used for Mars orbit insertion Propulsion Technology LH2/LOx for Earth departure with chemical LCH4/LOx for other maneuvers with chemical ISPP (if used) Each Mars mission carries plant Single base/production facility for Lunar missions

Defining the Architecture: 

Defining the Architecture Architecture is a representation of the Stable Properties of the system. It is the embodiment of a concept, and the allocation of physical/informational functions to elements of form, and definition of interfaces among the elements and with the surrounding context. Stable properties of a the Exploration architecture: The Mission Mode: the number, types, destinations and interactions of the exploration vehicles Number and Types of Vehicles Destinations of Vehicles Vehicle Interactions John C. Houbolt explains the mission mode Lunar Orbit Rendezvous (LOR) (NASA Photo)

Moon-Mars Architecture Generator: 

Moon-Mars Architecture Generator Constructed using OPN Produces 1162 unique transportation architectures. This model describes the set containing the entire space of alternatives. Relatively easy to add new options or behaviors, if necessary.

Instance of a Transportation Architecture: 

Instance of a Transportation Architecture #567 of 1162 generated mission modes Mass Metrics can be calculated for different configurations: Examples: This Architecture is representative of the 1993 NASA Mars Design Reference Mission

Comprehensive Study of Feasible Options: 

Comprehensive Study of Feasible Options Metrics were calculated for various configurations of all 1162 architectures Example: Total Initial Mass in Low Earth Orbit (IMLEO) MOON: Crew=5, ISRU=no, Propulsion=Chemical MARS: Crew=5, ISRU=no, Propulsion=Chemical Moon Mars

Results: Modular, Accretive and Minimal: 

Design Philosophy: Maximize hardware commonality to minimize gap between lunar and Mars missions and overall development and production costs CEV + IPU (27 m3 ): Integrated aeroshell Mars Mission Hardware LEO / ISS Mission Hardware Common in-space propulsion stage (LCH4 / LOX): Core propulsion stage XL strap-on tanks XXL strap-on tanks (ERV) Heavy Lift Launch Vehicle: (“2 stages”, 100 mt to LEO) Short Lunar Mission Hardware Habitat core and inflatable pressurized tent for planetary surfaces: Long Lunar Mission Hardware Note: Block upgrades across phases are not depicted LEO propulsion stage: CEV launch vehicle: CEV power pack: LAT for CEV capsule: SDLV upper stage (125 mt to LEO), potentially EDS-derived: Mars landing gear & exoskeleton: Engine 1 (LCH4 / LOX) Restartable, non-throttleable: Common Earth departure stage (LH2 / LOX) Engine 2 (LCH4 / LOX) Throttleable: Lunar landing gear & exoskeleton: Results: Modular, Accretive and Minimal

Slide50: 

Base Moon-Mars Exploration System Commonality Concept Lunar Transportation Architecture Mars Transportation Architecture With Mars-Back approach, most of the elements from the Lunar Mission are also useable for the Mars mission. Principle: Keep costs low by planning in commonality and extensibility from the beginning

Common Destination Vicinity Propulsion System: 

Common Destination Vicinity Propulsion System A Modular solution for Destination Vicinity Propulsion System: Common propulsion stage core employed in all use-cases (sized by Lunar Ascent & TEI) Duplicate set of tanks (relative to core) provides additional propellant for Lunar/Mars Descent and Mars Ascent Common ascent engines, common descent engines for Moon [2 engines] and Mars [4 engines] Moon Mars Crew Transport Surface Habitat Mars Ascent Vehicle Transfer and Surface Habitat Earth Return Vehicle

Key Questions in Architecture - Being Addressed!: 

Key Questions in Architecture - Being Addressed! How can we represent architectures? How can we rigorously search the option space? How can we select an architecture that has desirable value delivery? How can we identify the decisions that lead to the selection of a preferred architecture?

A New Research Partnership: 

A New Research Partnership University Research Education Industry Gov Labs “Laboratory” Learners Flow-down Results Org. Change Critique