上海交通大学：《Systems Engineering 系统工程》课程教学资源（电子讲义）Lecture6 Tradespace Exploration and Concept Selection：AHP Method

JIAOTONG UNIVERSIT 196 Systems Engineering Lecture 6 Tradespace Exploration and Concept Selection: AHP Method Instructor(s) Prof.Jianjun Gao Department of Automation School of Electronic Information and Electrical Engineering 2014 Spring

Systems Engineering Instructor(s) + - 2014 Spring Tradespace Exploration and Concept Selection: AHP Method Prof. Jianjun Gao Department of Automation School of Electronic Information and Electrical Engineering Lecture 6

Gao's V-Model Stakeholder Systems Engineering Lifecycle Analysis Overview Managment 入 Requirement Cost and Schedule Commissioning Analysis Management Operations System Verification and Architecture Validation Tradespace System Exploration Integration Human System Factor Design Definition and Safety Optimization CLGO System Engineering by J.J.Gao 2

+ - System Engineering by J. J. Gao 2 Gao’s V-Model Stakeholder Analysis Requirement Analysis System Architecture Tradespace Exploration Design Definition and Optimization System Integration Verification and Validation Commissioning Operations Lifecycle Managment Systems Engineering Overview Cost and Schedule Management Human Factor System Safety

Today's Agenda Analytic Hierarchy Process(AHP) Step by step Example of AHP Example CLGO System Engineering by J.J.Gao 3

+ -  Analytic Hierarchy Process(AHP)  Step by step Example of AHP  Example System Engineering by J. J. Gao 3 Today’s Agenda

The Analytic Hierarchy Process(AHP) Founded by Saaty in 1980. It is a popular and widely used method for multi-criteria decision making. Allows the use of qualitative,as well as quantitative criteria in evaluation. Wide range of applications in systems engineering CLGO

+ - The Analytic Hierarchy Process (AHP)  Founded by Saaty in 1980.  It is a popular and widely used method for multi-criteria decision making.  Allows the use of qualitative, as well as quantitative criteria in evaluation.  Wide range of applications in systems engineering

AHP Methodology in Trade Studies Prioritizes multiple tangible and intangible criteria: In most decisions,intangibles such as political factors and ·social factors take precedence over tangibles such as ·economic factors and ·technical factors ◆ It is not the precision of measurement on a particular factor that determines the validity of a decision,but the importance we attach to the factors involved AHP assigns importance to all the factors and synthesizes this diverse information to make the best decision Example:the decision to use aluminum instead of a titanium alloy for the Boeing 777 wings was not the technically preferred alternative. G CLGO System Engineering by J.J.Gao 5

+ - System Engineering by J. J. Gao 5 5 AHP Methodology in Trade Studies Prioritizes multiple tangible and intangible criteria:  In most decisions, intangibles such as • political factors and • social factors take precedence over tangibles such as • economic factors and • technical factors  It is not the precision of measurement on a particular factor that determines the validity of a decision, but the importance we attach to the factors involved  AHP assigns importance to all the factors and synthesizes this diverse information to make the best decision Example: the decision to use aluminum instead of a titanium alloy for the Boeing 777 wings was not the technically preferred alternative

AHP-General Idea Develop an hierarchy of decision criteria and define the alternative courses of actions. ■ It requires a step by step process of pairwise comparisons of options against each of the objectives. Then the objectives themselves must be compared and weighted. Each objective can have a collection of sub-objectives on which this process can be carried out,from where the hierarchy'originates. CLGO 6

+ - 6 AHP-General Idea  Develop an hierarchy of decision criteria and define the alternative courses of actions.  It requires a step by step process of pairwise comparisons of options against each of the objectives.  Then the objectives themselves must be compared and weighted.  Each objective can have a collection of sub-objectives on which this process can be carried out, from where the ‘hierarchy’ originates

AHP-General Idea AHP algorithm is basically composed of four steps: 1.Construct the hierarchy structure(Goal,Criteria, Alternatives) 2. Construct the pairwise comparison matrix 3.Compute the weight and check the consistency for one layer 4.Determine the relative rankings(priorities)of alternatives 5.Make the overall decision Both qualitative and quantitative information can be compared by using informed judgments to derive weights and priorities. System Engineering by J.J.Gao CLGO 7

+ -  AHP algorithm is basically composed of four steps: 1. Construct the hierarchy structure(Goal, Criteria, Alternatives) 2. Construct the pairwise comparison matrix 3. Compute the weight and check the consistency for one layer 4. Determine the relative rankings (priorities) of alternatives 5. Make the overall decision  Both qualitative and quantitative information can be compared by using informed judgments to derive weights and priorities. System Engineering by J. J. Gao 7 AHP-General Idea

AHP Detail Step 1.Construct the hierarchy structure(Goal,Criteria, Alternatives) Layer:O GOAL Layer:P CRITERIA Layer:S ALTERNATIVES CLGO System Engineering by J.J.Gao 8

+ - System Engineering by J. J. Gao 8 AHP Detail GOAL CRITERIA ALTERNATIVES Step 1. Construct the hierarchy structure(Goal, Criteria, Alternatives) Layer: P Layer: O Layer: S

AHP Detail Decision Frame Select a New Telemetry Solution Maintainability Reliability Option Schedule Operability Growth Confidence Risk Potential Supplier A GFE Option Supplier B CLGO System Engineering by J.J.Gao 9

+ - System Engineering by J. J. Gao 9 9 Operability Decision Frame Maintainability Reliability Schedule Risk Growth Potential Select a New Telemetry Solution Option Confidence Supplier A GFE Option Supplier B AHP Detail

Quick Exercise Objective:Selecting a job Criteria:salary,environment, career development,position,..... Alternatives:please specify yourself Construct the hierarchy structure. CLGO System Engineering by J.J.Gao 10

+ -  Objective: Selecting a job  Criteria: salary, environment, career development, position,…..  Alternatives: please specify yourself  Construct the hierarchy structure. System Engineering by J. J. Gao 10 Quick Exercise