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Lecture 3 Conceptual System Design & Introduction to Functional Allocation ISE 222 Spring 2005 Notes & Course Materials www.engr.sjsu.edu/kcorker Kevin.Corker@sjsu.edu. Kevin Corker San Jose State University 2/3/05. Steps/Perspectives for System Engineering (Formulation).
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Lecture 3 Conceptual System Design & Introduction to Functional Allocation ISE 222 Spring 2005Notes & Course Materials www.engr.sjsu.edu/kcorkerKevin.Corker@sjsu.edu Kevin Corker San Jose State University 2/3/05
Steps/Perspectives for System Engineering (Formulation) • Formulation of the System • Needs to be fulfilled • Requirements & Objectives • Constraints and Degrees of Freedom • Alternatives to above • Value System Design • Identification of the objectives and goals that guide alternative selection • Definition of multi-dimensional attributes or decision criteria • Identification and validation of objective measures • System Synthesis • Generation of alternative course of action and associated measures of effectiveness
Identification of Need • Gap • New Techniques • New System Requirements added • System Requirements Change Priority • Political Views Shift • … • Involve the customer– unless the customer has changed as well
Feasibility Analysis • Identify Possible System level Approaches • Eval for • Performance • Effectiveness • Manufacturability • Maintenance • Logistics Support • Recommend a course of action • (a few)
Identify Constraints • Limit Your Options • Specifications that must be met • Integration Standards that are mandated • Cost & Schedule Limitations • Missing Information • Missing Code • Missing SOA • Life Cycle Issues Identified
System Requirements Analysis (of feasible system set) • Ops Requirements • All Weather Operations • Maintenance Requirements • LRU with redundancy • Technical Performance Measure of alternatives • TPMs • Functional Analysis & Functional Allocation
System Specification Software System Hardware Test Equipment Simulation Reqs Range Reqs Integration Reqs Data Reqs Management Requirements Program Planning Control Version Control Test Data Dissemination Integration Reporting … System Requirements Technical Management
Operational Requirements • Deployment Range • Mission Profile • Performance Parameters • Range, size, accuracy , rate, power, weight, footprint, out gassing, lethality…… • Utilization Requirements • Duty cycle • Capacity • Stress
Operational Requirements • Effectiveness/Reliability • cost./benefit • Availability • Readiness rate • MTBF/MTBM • Failure rate • Maintenance • downtime • Personnel KSA (operations, upgrades & maintenance) • Immediate, preventative, upgrade/overhaul • Operational Lifecycle • Environment
Technical Performance Measures • Design Dependent Parameters • Quality Function Deployment • Belies the waterfall approach • House of Quality Approach • http://www.isixsigma.com/offsite.asp?A=Fr&Url=http://www.gsm.mq.edu.au/cmit/hoq/QFD%20Tutorial.swf
Action Reference Framework • To (do something) to (something) somehow • Action , object, modifier • Used to describe a process Functional Decomposition is to develop a description of what the system must do – not necessarily tied to how the system must do it.
Action/Task Action/Task Action/Task Action/Task Action/Task Action/Task Functional Flow Block Diagram Boolean Operator
Hierarchic Structure for Decomposition • Sub Functions operate on input/output consistent with the higher levels of the hierarchy • Models the flow of data or objects in a system
Major Functional Techniques • Structural Analysis Decision Technique (SADT) • Integrated Definition Language (IDEF) • IDEF 0 functional decomposition • IDEF 1 informational decomposition • Data Flow Diagrams/Control Diagrams
ICOM Control Activity Inputs Outputs Mechanism
Method of Analysis • Shows roles of information and materials with respect to activity • Each ICOM represents an activity or business step that can be broken down • Inputs: information/material used to produce activity output • Controls: Constraints on an activity • Mechanisms: That perform processing or provide energy to the activity (people or machines as mechanisms) • Output: The product of the activity
Context Diagram Control Activity Inputs Outputs A0 : Purpose : Viewpoint Mechanism
Steps in Functional Decomposition • Develop Context Diagram of Full System • Decompose System to Sub-elements (ICOMS fro all) • Define Business Rule/Model • AS-Is the descriptive scenario • To-Be the future business or process model • Analysis of activities, gather costs, trace costs to activities, establish output measures, analyze costs
Steps/Perspectives for System EngineeringAnalysis • System Analysis & Modeling • Identification of the impacts and consequences of alternative approaches to system solution • Identification of the quality, market, reliability, cost, effectiveness, benefits, longevity, aesthetics… of alternative system solutions • Iterative Refinement of Alternatives • Sensitivity Analysis and Parameter Identification