1. Session 11a Dr. Dan C. Surber, ESEP
ME Fall Introduction to Systems Engineering
Session 11a
Dr. Dan C. Surber, ESEP
© Copyright 2013

2. Lecture Topics
Trade Study Methods
Trade Study Reports

3. Trade Study Methods Purpose Methodology Scoring
Criteria
Weighting of criteria
Utility curves
Alternatives
Scoring
Compare attribute of each alternative to criteria
Obtain score from utility curve
Multiply score by weighting = weighted score
Conduct sensitivity analysis
Shift score by +/- 10% and see if end result is same
Re-visit sensitive criteria

4. Follow a Process NO-GO CRITERIA Criteria for valid alternatives
Utility curves for each criterion
Weight the criteria
Gather data about the alternatives
Filter the alternatives through NO-GO
Evaluate the “cleared” alternatives
Sensitivity analysis
Assess the risk of adopting the recommended alternative
Publish the report

5. Example WORKSHEET Raytheon uses an MS EXCEL Workbook.
Use tools that capture the data for archival.
Retain for the life of the project.
Write a report using these data after the trade study is completed.
Use a template for your process if you do LOTS & LOTS of these trades.

6. Example of Worksheet

7. Usually it’s best to draw a utility curve for each criterion.
Utility Curve Example
Usually it’s best to draw a utility curve for each criterion.

8. Worksheet See MS Excel worksheet in HANDOUTS
Students draw a couple of UTILITY CURVES
Compute the UTILITY of the RAW SCORE
Select the BEST CANDIDATE

9. Trade Study Reporting Purpose Get the 5 “W’s”
Who, what, where, when, why and how
Explain rationale for alternatives NOT scored
Retain in project archives as part of project baseline
Do it in a tool/data base to make it easy to access later on if needed

10. Pugh Concept Selection
Purpose
Base, criterion (10 to 20) and Alternatives
Compare each alternative to Base
Scores are “+, 0, -”
Best Score is NEW Base
Discover new alternatives as hybrids
Re-score, final winner must be feasible

11. Pugh Looked for the HYBRID
Choose the “BEST”
Characteristic
Of Each
Candidate
&
Create HYBRID
Options
Identify
Feasible
Candidates
&
Scoring
Criteria
Evaluate
Each
Option
THE WINNER
Choose NEW BASE & Evaluate Each Option
Select a BASE to compare options to