The Decision Analysis and Resolution (DAR) Process Terry Bahill Systems and Industrial Engineering University of Arizona [email protected] ©, 2005-09,

The Decision Analysis and The Decision Analysis and Resolution (DAR) ProcessResolution (DAR) Process

Terry BahillSystems and Industrial EngineeringUniversity of [email protected]©, 2005-09, BahillThis file is located at

http://www.sie.arizona.edu/sysengr/slides/

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CMMI The CMMI model is a collection of best practices

from diverse engineering companies. Improvements to our organization will come from

process improvements, not from people improvements or technology improvements.

CMMI provides guidance for improving an organization’s processes.

One of the CMMI process areas is Decision Analysis and Resolution, DAR.

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DAR Programs and Functions select the decision

problems that require DAR and incorporate them in their program plans (e.g. SEMPs).

DAR is a BAE SYSTEMS common process. Common processes are tools that the user gets, customizes and uses.

DAR is invoked throughout the whole program lifecycle whenever a critical decision is to be made.

DAR is invoked by IPT leads on programs, financial analysts, program core teams, etc.

Invoke the DAR Process in Webster work instructions, in gate reviews, in phase reviews or with other triggers, which can be used anytime in the system life cycle.

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WebsterBAE’s common processes are established by SP.12.15.02.

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Typical decisions Decision problems that may require a formal

decision process Trade studies (eng_cat.shtml#GU0238) Bid/no-bid Make-reuse-buy (PW.10.01.01A017.html) Fagan inspection versus checklist inspection

(FM.05-1077.xls) Tool selection Vendor selection Cost estimating

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Purpose“In all decisions you gain something and lose something. Know what they are and do it deliberately.”

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A Simple Model for A Simple Model for Human Decision Making,Human Decision Making,

Called Image TheoryCalled Image Theory

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References The following description of image theory is based

on Beach and Connolly (2005) and Bruce Gissing’s Roadmap to Business Excellence.

L. R. Beach and T. Connolly, The Psychology of Decision Making: People in Organizations, Sage Publications, Thousand Oaks, CA, 2005.

B. Gissing, The Roadmap to Business Excellence, http://sie.arizona.edu/sysengr/sie554/BruceGissing/RoadMap.ppt, 2005.

A. T. Bahill and B. Gissing, Re-evaluating systems engineering concepts using systems thinking, IEEE Transactions on Systems, Man, and Cybernetics, Part C: Applications and Reviews, SMC-28(4): 516-527, 1998.

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Image theory*

Decision Makers (DMs) code their knowledge into three images.

The value image contains principles of behavior. The trajectory image is the agenda of goals. The strategic image contains the plans for

implementing the goals.

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The value imageconsists of the DM’s vision, mission, values, morals,

ethics, beliefs, evaluation criteria and standards for how things should be and how people ought to behave.

Collectively these are called principles. They limit

the goals that are worthy of pursuit and acceptable ways of pursuing these goals.

Potential goals and actions that contradict the principles will be unacceptable.

It is called the value image because it represents the DM’s vision about the state of events that conforms most closely to his or her principles.

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The trajectory imageis the agenda of goals the DM wants to achieve. The goals are dictated by the problem statement,

principles, opportunities, desires, competitive issues and gaps encountered in the environment.

The goals are fed back to the value image. The DM’s goal agenda is called the trajectory

image, because it is his or her vision about how the future should unfold.

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The strategic imagecontains the plans for implementing the goals. Each plan has two aspects:

tactics are the concrete behavioral aspects that deal with local environment conditions,

forecasts are the anticipation of the future that describe what might result if the tactics are successful.

The plans are also fed back to the value image. The collection of plans is called the strategic

image, because it represents the DM’s vision of what he or she is trying to do to achieve the goals on the trajectory image.

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Framing*

means embedding observed events in a context that gives them meaning.

The DM uses contextual information to probe his or her memory to find image constituents that are relevant to the decision at hand.

This provides information about the goals and plans that were previously pursued in this context.

If a similar goal is being pursued this time, then the plan that was used before may be reused.

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Two types of decisions Adoption decisions determine whether to add new

goals to the trajectory image or new plans to the strategic image.

Progress decisions determine whether a plan is making progress toward achieving a goal.

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Adoption decisions A new goal or plan can be added if it is compatible

with the DM’s relevant principles, does not introduce unacceptable risk and does not interfere with existing goals or ongoing plans.

Adoption decisions are accomplished by screening potential goals and plans one by one in

light of relevant principles, existing goals and ongoing plans. If only one option passes screening, it is adopted.

If two or more options pass the screen, then a tradeoff study determines the best option from among the survivors.

Screening is the more common of these decision mechanism.

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Progress decisionsuse the plan to forecast the future.

If that future includes achieving a goal, then the plan is retained.

If the forecast does not include achieving the goal, then the plan is rejected and a new plan is adopted in its place.

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Two decision mechanisms The incompatibility test screens options based on

how well they fit the DM’s images. The profitability test focuses on the quality of the

outcomes associated with the options.

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The incompatibility testscreens options (plans and goals) based on their

incompatibility with constituents* defined in the three images.

Each option’s incompatibility increases as a function of the weighted sum of the number of violations.**

Violations are defined as negations, contradictions, preventions, retardations or any other form of interference with the realization one of the images’ constituents.

If the weighted sum of the violations exceeds some rejection threshold, then the option is rejected, otherwise it is adopted.

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Profitability test When more than one option survives the

incompatibility screen, the DM chooses the best using a profitability test.

The profitability test is not a single decision mechanism.

It is a repertory of strategies such as maximizing subjective expected utility, satisficing and performing tradeoff studies.

The selected strategy depends on characteristics of the choice, characteristics of the environment, characteristics of the DM.

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Image theory for organizations*

Decisions in organizations are made by individual DMs, often forming a consensus.

So for organizational decisions, we can use the individual decision making model that we have just developed.

The only major addition is the need for a case for change.

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The need for change*

People do not make good decisions.

A careful tradeoff study will help you overcome human ineptitude and thereby make better decisions.

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Rational decisions*

One goal Perfect information The optimal course of action can be described This course maximizes expected value

This is a prescriptive model. We tell people that, in an ideal world, this is how they should make decisions.

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Satisficing*

When making decisions there is always uncertainty, too little time and insufficient resources to explore the whole problem space.

Therefore, people cannot make rational decisions.

The term satisficing was coined by Noble Laureate Herb Simon in 1955.

Simon proposed that people do not attempt to find an optimal solution. Instead, they search for alternatives that are good enough, alternatives that satisfice.

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Humans are not rational*1

Mark Twain said, “It ain’t what you don’t know that gets you into

trouble. It’s what you know for sure that just ain’t so.”

Humans are often very certain of knowledge that is false. What American city is directly north of Santiago

Chile? If you travel from Los Angeles to Reno Nevada, in

what direction would you travel? Most humans think that there are more words that

start with the letter r, than there are with r as the third letter.

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Illusions*

We call these cognitive illusions. We believe them with as much certainty as we

believe optical illusions.

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The Müller-Lyer Illusion*

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ObjectiveProbability

SubjectiveProbability

EVRational Behavior V

Subjective Expected Value

Human Behavior

EExpected Utility

Value

Utility

Typical Estimate

0.00.0

1.0

1.0

Ideal Estimate

Ideal Estimate

1.00.00.0

1.0

Typical Estimate

Subjective Worth

Objective Value

Referencepoint

Gains

Losses

Objective Value

Subjective Worth Gains

LossesReference

point

Real Probability

Real Probability

Su

bje

ctiv

e P

rob

ab

ility

We

igh

ting

Su

bje

ctiv

e P

rob

ab

ility

We

igh

ting

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Humans judge probabilities poorly*

0.00.0

1.0

1.0

Ideal Estimate

Typical Estimate

Real Probability

Su

bje

ctiv

e P

rob

ab

ility

We

igh

ting

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Monty Hall Paradox1*

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Now here is your problem. Are you better off sticking to your original choice

or switching? A lot of people say it makes no difference. There are two boxes and one contains a ten-

dollar bill. Therefore, your chances of winning are 50/50. However, the laws of probability say that you

should switch.

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The box you originally chose has, and always will have, a one-third probability of containing the ten-dollar bill.

The other two, combined, have a two-thirds probability of containing the ten-dollar bill.

But at the moment when I open the empty box, then the other one alone will have a two-thirds probability of containing the ten-dollar bill.

Therefore, your best strategy is to always switch!

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Utility We have just discussed the right column, subjective

probability. Now we will discuss the bottom row, utility





Human Behavior

EExpected Utility

Value

Utility

Typical Estimate

0.00.0

1.0

1.0

Ideal Estimate

Ideal Estimate

1.00.00.0

1.0

Typical Estimate

Subjective Worth

Objective Value

Referencepoint

Gains

Losses

Objective Value


LossesReference

point

Real Probability

Real Probability

Sub

ject

ive

Pro

ba

bili

ty W

eig

htin

gS

ub

ject

ive

Pro

ba

bili

ty W

eig

htin

g

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UtilityUtility is a measure of the happiness, satisfaction or reward a person gains (or loses) from receiving a good or service.

Utilities are numbers that express relative preferences using a particular set of assumptions and methods.

Utilities include both subjectively judged value and the assessor's attitude toward risk.

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Risk Systems engineers use risk to evaluate and manage bad

things that could happen, hazards. Risk is measured with the frequency (or probability) of occurrence times the severity of the consequences.

However, in economics and in the psychology of decision making, risk is defined as the variance of the expected value, uncertainty.*

p1 x1 p2 x2 Risk, uncertainty

A 1.0 $10 $10 $0 none

B 0.5 $5 0.5 $15 $10 $5 medium

C 0.5 $1 0.5 $19 $10 $9 high

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Ambiguity, uncertainty and hazards* Hazard: Would you prefer my forest picked

mushrooms or portabella mushrooms from the grocery store?

Uncertainty: Would you prefer one of my wines or a Kendall-Jackson merlot?

Ambiguity: Would you prefer my saffron and oyster sauce or marinara sauce?

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Humans are not rational Even if they had the knowledge and resources,

people would not make rational decisions, because they do not evaluate utility rationally.

Most people would be more concerned with a large potential loss than with a large potential gain. Losses are felt more strongly than equal gains.

Which of these wagers would you prefer to take?*$2 with probability of 0.5 and $0 with probability 0.5$1 with probability of 0.99 and $1,000,000 with

probability 0.00000001$3 with probability of 0.999999 and -$1,999,997 with

probability 0.000001 They all have an expected value of $1

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Gains and losses are not valued equally*

Gains

Losses

ObjectiveValue

Reference Point

SubjectiveWorth

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Subjective expected utilitycombines two subjective concepts: utility and

probability. Utility is a measure of the happiness or

satisfaction a person gains from receiving a good or service.

Subjective probability is the person’s assessment of the frequency or likelihood of the event occurring.

The subjective expected utility is the product of the utility times the probability.

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Subjective expected utility theorymodels human decision making as maximizing

subjective expected utility maximizing, because people choose the set of

alternatives with the highest total utility, subjective, because the choice depends on the

decision maker’s values and preferences, not on reality (e.g. advertising improves subjective perceptions of a product without improving the product), and

expected, because the expected value is used. This is a first-order model for human decision

making. Sometimes it is called Prospect Theory*.

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Human Behavior

EExpected Utility

Value

Utility

Typical Estimate

0.00.0

1.0

1.0

Ideal Estimate

Ideal Estimate

1.00.00.0

1.0

Typical Estimate

Subjective Worth

Objective Value

Referencepoint

Gains

Losses

Objective Value


LossesReference

point

Real Probability

Real Probability

Su

bje

ctiv

e P

rob

ab

ility

We

igh

ting

Su

bje

ctiv

e P

rob

ab

ility

We

igh

ting

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Why teach tradeoff studies? Because emotions, cognitive illusions, biases,

fallacies, fear of regret and use of heuristics make humans far from ideal decision makers.

Using tradeoff studies judiciously can help you make rational decisions.

We would like to help you move your decisions from the normal human decision-making lower-right quadrant to the ideal decision-making upper-left quadrant.

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The Decision Analysis and Resolution The Decision Analysis and Resolution Proces (DAR)Proces (DAR)

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Specific goals (SG)A specific goal applies to a process area and addresses the unique characteristics that describe what must be implemented to satisfy the process area. The specific goal for the DAR process area is

SG 1 Evaluate Alternatives.

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Specific practices (SP) A specific practice is an activity that is

considered important in achieving the associated specific goal.

Practices are the major building blocks in establishing the process maturity of an organization.

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SpecificPracticeNumber

DAR

Specific Practice Name

Example

1.1 Decide if formal evaluation process is warranted

When to do a trade study

1.2 Establish Evaluation Criteria

What is in a good trade study

1.3 Identify Alternative Solutions

1.4 Select Evaluation Methods

1.5 Evaluate Alternatives

1.6 Select Preferred Solutions

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The Decision Analysis and Resolution (DAR) Process

SelectEvaluationMethods

EvaluateAlternatives

PreferredSolutions

SelectSolutions

EstablishEvaluation

Criteria

EvaluationCriteria

IdentifyAlternativeSolutions

ProposedAlternatives

SelectionProblem

Decide if Formal

Evaluation Process is Warranted

ProblemStatement S

Manage the DAR process

Recommendations

FormalEvaluations

These tasks are drawn serially, but they are not performed in a serial manner. Rather it is an iterative process with many unshown feedback loops.

Decision to Not Proceed

ExpertReview

Put in PAL

Present Results to Decision

Maker

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When creating a process the most important facets are illustrating tasks that can be done in parallel suggesting feedback loops including a process to improve the process configuration management

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A simple tradeoff study

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Decisions Humans make four types of decisions:

Allocating resources among competing projects* Making plans, which includes scheduling Negotiating agreements Choosing amongst alternatives

Alternatives can be examined in series or parallel. When examined in series it is called sequential

search When examined in parallel it is called a tradeoff or

a trade study “Tradeoff studies address a range of problems

from selecting high-level system architecture to selecting a specific piece of commercial off the shelf hardware or software. Tradeoff studies are typical outputs of formal evaluation processes.”*

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HistoryBen Franklin’s letter* to Joseph Priestly outlined one of the first descriptions of a tradeoff study.

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Tradeoff Study ProcessTradeoff Study Process**

These tasks are drawn serially,but they are not performed in a serial manner. Rather, it is an iterative processwith many feedback loops, which are not shown.

Decide if FormalEvaluation is

Needed


Needed

Problem StatementProblem

Statement

SelectEvaluation Methods


Establish Evaluation

Criteria


Criteria

Identify AlternativeSolutions


ProposedAlternativesProposed

Alternatives

EvaluationCriteria

EvaluationCriteria



Select PreferredSolutions


Formal Evaluations

Formal Evaluations

PerformExpert Review


Preferred SolutionsPreferred Solutions

Present ResultsPresent Results

Put In PPAL

Put In PPAL

∑

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Decide if Formal Evaluation is NeededDecide if Formal Evaluation is Needed

Decide ifDecide if FormalFormalEvaluation isEvaluation is

Needed Needed


Statement




Criteria


Criteria




Alternatives

EvaluationCriteria

EvaluationCriteria





Formal Evaluations

Formal Evaluations





Put In PPAL

Put In PPAL

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Is formal evaluation needed? SP 1.1Companies should have polices for when to do

formal decision analysis. Criteria include When the decision is related to a moderate or high-

risk issue When the decision affects work products under

configuration management When the result of the decision could cause

significant schedule delays When the result of the decision could cause

significant cost overruns On material procurement of the 20 percent of the

parts that constitute 80 percent of the total material costs

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Guidelines for formal evaluation, SP 1.1 When the decision is selecting one or a few

alternatives from a list When a decision is related to major changes in work

products that have been baselined When a decision affects the ability to achieve project

objectives When the cost of the formal evaluation is reasonable

when compared to the decision’s impact On design-implementation decisions when technical

performance failure may cause a catastrophic failure On decisions with the potential to significantly reduce

design risk, engineering changes, cycle time or production costs

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Establish Evaluation CriteriaEstablish Evaluation Criteria


Needed


Needed


Statement



Establish Establish EvaluationEvaluation

CriteriaCriteria




Alternatives

EvaluationCriteria

EvaluationCriteria





Formal Evaluations

Formal Evaluations





Put In PPAL

Put In PPAL

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Establish evaluation criteria* SP 1.2 Establish and maintain criteria for evaluating alternatives Each criterion must have a weight of importance Each criterion should link to a tradeoff requirement, i.e. a

requirement whose acceptable value can be more or less depending on quantitative values of other requirements.

Criteria must be arranged hierarchically. The top-level may be performance, cost, schedule and risk.

Program Management should prioritize these four criteria at the beginning of the project and make sure everyone knows the priorities.

All companies should have a repository of generic evaluation criteria.

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What will you eat for lunch today? In class exercise. Write some evaluation criteria that will, help you

decide.*

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Killer trades Evaluating alternatives is expensive. Therefore, early in tradeoff study, identify very

important requirements* that can eliminate many alternatives.

These requirements produce killer criteria.** Subsequent killer trades can often eliminate 90%

of the possible alternatives.

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Identify Alternative SolutionsIdentify Alternative Solutions


Needed


Needed


Statement




Criteria


Criteria

Identify Identify AlternativeAlternativeSolutionsSolutions


Alternatives

EvaluationCriteria

EvaluationCriteria





Formal Evaluations

Formal Evaluations





Put In PPAL

Put In PPAL

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Identify alternative solutions, SP 1.3 Identify alternative solutions for the problem

statement Consider unusual alternatives in order to test the

system requirements* Do not list alternatives that do not satisfy all

mandatory requirements** Consider use of commercial off the shelf and in-

house entities***

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What will you eat for lunch today? In class exercise. List some alternatives for today’s lunch.*

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Select Evaluation MethodsSelect Evaluation Methods


Needed


Needed


Statement

SelectSelectEvaluation Evaluation MethodsMethods


Criteria


Criteria




Alternatives

EvaluationCriteria

EvaluationCriteria





Formal Evaluations

Formal Evaluations





Put In PPAL

Put In PPAL

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Select evaluation methods, SP 1.4 Select the source of the evaluation data and the

method for evaluating the data Typical sources for evaluation data include

approximations, product literature, analysis, models, simulations, experiments and prototypes*

Methods for combining data and evaluating alternatives include Multi-Attribute Utility Technique (MAUT), Ideal Point, Search Beam, Fuzzy Databases, Decision Trees, Expected Utility, Pair-wise Comparisons, Analytic Hierarchy Process (AHP), Financial Analysis, Simulation, Monte Carlo, Linear Programming, Design of Experiments, Group Techniques, Quality Function Deployment (QFD), radar charts, forming a consensus and Tradeoff Studies

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Collect evaluation data Using the appropriate source (approximations,

product literature, analysis, models, simulations, experiments or prototypes) collect data for evaluating each alternative.

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Evaluate AlternativesEvaluate Alternatives


Needed


Needed


Statement




Criteria


Criteria




Alternatives

EvaluationCriteria

EvaluationCriteria

EvaluateEvaluateAlternativesAlternatives



Formal Evaluations

Formal Evaluations





Put In PPAL

Put In PPAL

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Evaluate alternatives, SP 1.5Evaluate alternative solutions using the evaluation criteria, weights of importance, evaluation data, scoring functions and combining functions.

Evaluating alternative solutions involves analysis, discussion and review. Iterative cycles of analysis are sometimes necessary. Supporting analyses, experimentation, prototyping, or simulations may be needed to substantiate scoring and conclusions.

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Select Preferred SolutionsSelect Preferred Solutions


Needed


Needed


Statement




Criteria


Criteria




Alternatives

EvaluationCriteria

EvaluationCriteria



Select Select PreferredPreferredSolutionsSolutions

Formal Evaluations

Formal Evaluations



Preferred Preferred SolutionsSolutions


Put In PPAL

Put In PPAL

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Select preferred solutions, SP 1.6 Select preferred solutions from the alternatives

based on evaluation criteria. Selecting preferred alternatives involves weighing

and combining the results from the evaluation of alternatives. Many combining methods are available.

The true value of a formal decision process might not be listing the preferred alternatives. More important outputs are stimulating thought processes and documenting their outcomes.

A sensitivity analysis will help validate your recommendations.

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Perform Expert ReviewPerform Expert Review


Needed


Needed


Statement




Criteria


Criteria




Alternatives

EvaluationCriteria

EvaluationCriteria





Formal Evaluations

Formal Evaluations

Perform Expert Review

Perform Expert Review



Put In PPAL

Put In PPAL

∑

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Perform expert review1

Formal evaluations should be reviewed* at regular gate reviews such as SRR, PDR and CDR or by special expert reviews

Technical reviews started about the same time as Systems Engineering, in 1960. The concept was formalized with MIL-STD-1521 in 1972.

Technical reviews are still around, because there is evidence that they help produce better systems at less cost.

The Perform Expert Review process is located at PS0303

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Perform expert review2

Technical reviews evaluate the product of an IPT* They are conducted by a knowledgeable board of

specialists including supplier and customer representatives

The number of board members should be less than the number of IPT members

But board expertise should be greater than the IPT’s experience base

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Who should come to the review? Program Manager Chief Systems Engineer Review Inspector Lead Systems Engineer Domain Experts IPT Lead Facilitator Stakeholders for this decision

Builder Customer Designer Tester PC Server

Depending on the decision, the Lead Hardware Engineer and the Lead Software Engineer

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Present resultsPresent the results* of the formal evaluation to the original decision maker and other relevant stakeholders.

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Put in the PAL Formal evaluations reviewed by experts should

be put in the organizational Process Asset Library (PAL) or the Project Process Asset Library (PPAL) (e.g. GDE 11 for M601)

Evaluation data for tradeoff studies come from approximations, analysis, models, simulations, experiments and prototypes. Each time better data is obtained the PAL should be updated.

Formal evaluations should be designed with reuse in mind.

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Manage the DAR process The DAR Process Owner shall manage and

improve the DAR process. The DAR Process Owner will establish a change

control board and review the DAR Common Process on a regular basis. This is a high-level review of the DAR Common Process. This review must evaluate the activities, status and results of the DAR process. For instance, it might address use of and training for the many methods of performing DAR.

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Closed Book Quiz, 5 minutes Closed Book Quiz, 5 minutes Fill in the empty boxesFill in the empty boxes


Statement


Alternatives

EvaluationCriteria

EvaluationCriteria

Formal Evaluations

Formal Evaluations

Preferred SolutionsPreferred Solutions∑

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Tradeoff Study ExampleTradeoff Study Example

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Example: What method should we use for evaluating alternatives?*

Is formal evaluation needed? SP 1.1 Check the Guidance for Formal Evaluations We find that many of its criteria are satisfied

including “On decisions with the potential to significantly reduce design risk … cycle time ...”

Establish evaluation criteria, SP 1.2 Ease of Use Familiarity

Killer criterion Engineers must think that use of the technique is

intuitive.

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Example (continued)1 Identify alternative solutions, SP 1.3

Linear addition of weight times scores, Multiattribute Utility Theory (MAUT).* This method is often called a “trade study.” It is often implemented with an Excel spreadsheet.

Analytic Hierarchy Process (AHP)**

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Example (continued)2 Select evaluation methods, SP 1.4

The evaluation data will come from expert opinion Common methods for combining data and

evaluating alternatives include: Multi-Attribute Utility Technique (MAUT),

Decision Trees, Analytic Hierarchy Process (AHP), Pair-wise Comparisons, Ideal Point, Search Beam, etc.

In the following slides we will use two methods: linear addition of weight times scores (MAUT) and the Analytic Hierarchy Process (AHP)*

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Example (continued)3 Evaluate alternatives, SP 1.5

Let the weights and evaluation data be integers between 1 and 10, with 10 being the best. The computer can normalize the weights if necessary.

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Multi-Attribute Utility Technique (MAUT)1

Criteria Weight of

Importance MAUT AHP

Ease of Use

8 4

Familiarity Sum of weight times score

Assess evaluation data* row by row

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Multi-Attribute Utility Technique (MAUT)2

Criteria Weight* of Importance

MAUT AHP

Ease of Use

9 8 4

Familiarity 3 9 2 Sum of weight times score

99 42

The

winner

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Analytic Hierarchy Process (AHP)

Verbal scale Numerical

value Equally important, likely or preferred

1

Moderately more important, likely or preferred

3

Strongly more important, likely or preferred

5

Very strongly more important, likely or preferred

7

Extremely more important, likely or preferred

9

Verbal scale Numerical

value Equally important, likely or preferred

1

Moderately more important, likely or preferred

3

Strongly more important, likely or preferred

5

Very strongly more important, likely or preferred

7

Extremely more important, likely or preferred

9

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AHP, make comparisonsCreate a matrix with the criteria on the diagonal and

make pair-wise comparisons*

Ease of Use Ease of Use is moderately more important than Familiarity (3)

Reciprocal of 3 = 1/3 Familiarity

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AHP, compute weights Create a matrix Square the matrix Add the rows Normalize*

1 1 23 3 3

1 3 1 3 2 6 8

1 1 2 2

0.7

. 5.6

5

0 27

1 1 23 3 3

1 3 1 3 2 6 8

1 1 2 2

0.7

. 5.6

5

0 27

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In-class exercise Use these criteria to help select your lunch today.

Closeness, distance to the venue. Is it in the same building, the next building or do you have to get in a car and drive?

Tastiness, including gustatory delightfulness, healthiness, novelty and savoriness.

Price, total purchase price including tax and tip.

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To help select lunch today1

closeness is ??? more important than tastiness, closeness is ??? more important than price, tastiness is ??? more important than price.

Closeness Tastiness Price

Closeness

Tastiness

Price

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closeness is strongly more important (5) than tastiness,

closeness is very strongly more important (7) than price,

tastiness is moderately more important (3) than price.

Closeness Tastiness Price

Closeness 1 5 7

Tastiness 1 3

Price 1

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1 5 7 1 5 7

3 12.3 29 44.3 0.731 1

1 3 1 3 0.8 3 7.4 11.2 0.195 5

0.4 1.4 3 4.8 0.081 1 1 1

1 17 3 7 3

Closeness Tastiness Price Weight of Importance

Closeness 1 5 7 0.73

Tastiness 1/5 1 3 0.19

Price 1/7 1/3 1 0.08

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AHP, get scores Compare each alternative on the first criterion

1 12 2

1 2 1 2 2 4 6

1 1 1 2 3

0.67

0.33

1 12 2

1 2 1 2 2 4 6

1 1 1 2 3

0.67

0.33

Ease of Use MAUT In terms of Ease

of Use, MAUT is slightly preferred (2)

1/2 AHP

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AHP, get scores2 Compare each alternative on the second criterion

1 15 5

1 5 1 5 2 10 0.83

0.17

12

1 1 0.4 2 2.4

1 15 5

1 5 1 5 2 10 0.83

0.17

12

1 1 0.4 2 2.4

Familiarity MAUT In terms of

Familiarity, MAUT is strongly preferred (5)

1/5 AHP

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AHP, form comparison matrix**

Combine with linear addition*

Criteria Weight of

Importance MAUT AHP

Ease of Use

0.75 0.67 0.33

Familiarity 0.25 0.83 0.17 Sum of weight times score

0.71 0.29

The

winner

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Example (continued)4

Select Preferred Solutions, SP 1.6 Linear addition of weight times scores (MAUT)

was the preferred alternative Now consider new criteria, such as Repeatability

of Result, Consistency*, Time to Compute Do a sensitivity analysis

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Sensitivity analysis, simpleIn terms of Familiarity, MAUT was strongly preferred (5) over the AHP. Now change this 5

to a 3 and to a 7.

• Changing the scores for Familiarity does not change the recommended alternative.

• This is good.• It means the Tradeoff study is robust with

respect to these scores.

Final Score Familiarity MAUT AHP

3 0.69 0.31 5 0.71 0.29 7 0.72 0.28

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Sensitivity analysis, analyticCompute the six semirelative-sensitivity functions, which are defined as

which reads, the semirelative-sensitivity function of the performance index F with respect to the parameter is the partial derivative of F with respect to times with everything evaluated at the normal operating point (NOP).

F

NOP

FS

FNOP

FS

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Sensitivity analysis2

For the performance index use the alternative rating for MAUT minus the alternative rating for AHP*

F = F1 - F2 = Wt1×S11 + Wt2×S21 – Wt1×S12 –Wt2×S22

Criteria Weight of

Importance MAUT AHP

Ease of Use

Wt1 S11 S12

Familiarity Wt2 S21 S22 Sum of weight times score

F1 F2

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The semirelative-sensitivity functions*

1

2

11

21

12

22

11 12 1

21 22 2

1 11

2 21

1 12

2 22

0.26

0.16

0.50

0.21

-0.25

-0.04

FWt

FWt

FS

FS

FS

FS

S S S Wt

S S S Wt

S Wt S

S Wt S

S Wt S

S Wt S

S11 is the most importantparameter. So go back and reevaluate it.

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The most important parameter is the score for MAUT on the criterion Ease of Use

We should go back and re-evaluate the derivation of that score

Ease of Use MAUT In terms of Ease

of Use, MAUT is slightly preferred (2)

1/2 AHP

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The Decision Analysis and Resolution (DAR) Process

SelectEvaluationMethods


PreferredSolutions

SelectSolutions

EstablishEvaluation

Criteria

EvaluationCriteria

IdentifyAlternativeSolutions

ProposedAlternatives

SelectionProblem

Decide if Formal

Evaluation Process is Warranted

ProblemStatement S

Manage the DAR process

Recommendations

FormalEvaluations

These tasks are drawn serially, but they are not performed in a serial manner. Rather it is an iterative process with many unshown feedback loops.

Decision to Not Proceed

ExpertReview

Put in PAL

Present Results to Decision

Maker

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Example (continued)5

Perform expert review of the tradeoff study. Present results to original decision maker. Put tradeoff study in PAL. Improve the DAR process.

Add some other techniques, such as AHP, to the DAR web course

Fix the utility curves document Add image theory to the DAR process Change linkages in the documentation system Create a course, Decision Making and Tradeoff Studies

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Quintessential exampleA Tradeoff Study of Tradeoff Study Tools

is available at

http://www.sie.arizona.edu/sysengr/sie554/tradeoffStudyOfTradeoffStudyTools.doc

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Generic goals (GG) Achievement of a generic goal in a process

area signifies improved control in planning and implementing the processes associated with that process area. Generic goals are called “generic” because the

same goal statement appears in (almost) all process areas.

Each process area has only one generic goal for each maturity level.

And the generic goal is different for each maturity level.

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Maturity level 2 generic goal GG 2: The DAR process is institutionalized as

a managed process. A managed process is a performed process

that is planned and executed in accordance with policy; employs skilled people having adequate resources to produce controlled outputs; involves relevant stakeholders; is monitored, controlled, and reviewed; and is evaluated for adherence to its process description.

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Maturity level 3 generic goal GG 3 The DAR process is institutionalized as a

defined process. A defined process is establish by tailoring the

selected process according to the organization’s tailoring guidelines to meet the needs of a project or organizational function. With a defined process, variability in how the process is performed across the organization is reduced and process assets, data, and learning can be effectively shared.

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Generic practices (GP) Generic practices contribute to the achievement

of the generic goal when applied to a particular process area.

Generic practices are activities that ensure that the processes associated with the process area will be effective, repeatable, and lasting.

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Generic practices1

GP 2.1: Establish an Organizational Policy,

Establish and maintain an organizational policy for planning and performing the DAR process.

The BAE solution SP.12.15.02 Organizational Business Practices

OM.12.15.02A001 Perform Decision Analysis and ResolutionRW.12.01.00A004 Perform Formal Evaluation

RF 1 Quantitative Methods for Tradeoff Analyses.doc…RF 12 Manage and Improve the DAR Process.doc

These documents are located at Users at Bluelnk\Bludfs001\Shared\Users\Bahill_AT\Draft DAR Process Docs

And O:\ENGR_LIB\SysPCRDocs\Reference Docs

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Generic practices2

GP 3.1 Establish and maintain the description of a defined decision analysis and resolution process.

BAE company compliance documents SP.12.15.02 Organizational Business Practices

OM.12.15.02A001 Perform Decision Analysis and ResolutionRW.12.01.00A004 Perform Formal Evaluation

BAE program implementation evidenceTailoring reports, program plans and trade studies

with evidence of use of SP 1.2 to 1.6.

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Generic practices3

GP 2.2: Plan the Process,

Establish and maintain the plan for performing the DAR process.

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Generic practices4

GP 2.3: Provide Resources,

Provide adequate resources for performing the DAR process, developing the work products, and providing the services of the process.

GP 2.4: Assign Responsibility,

Assign responsibility and authority for performing the process, developing the work products, and providing the services of the DAR process.

GP 2.5: Train People,

Train the people performing or supporting the DAR process as needed.

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Generic practices5 GP 2.6: Manage Configurations,

Place designated work products of the DAR process under appropriate levels of configuration management.

GP 2.7: Identify and Involve Relevant Stakeholders,

Identify and involve the relevant stakeholders of the DAR process as planned.

GP 2.8: Monitor and Control the Process,

Monitor and control the DAR process against the plan for performing the process and take appropriate corrective action.

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Generic practices6

GP 3.2 Collect Improvement Information such as work products, measures, measurement results, and improvement information derived from planning and performing the decision analysis and resolution process to support the future use and improvement of the organization’s processes and process assets.

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Generic practices7

GP 2.9: Objectively Evaluate Adherence,

Objectively evaluate adherence of the DAR process against its process description, standards, and procedures, and address noncompliance.

GP 2.10: Review Status with Higher Level Management,

Review the activities, status, and results of the DAR process with higher level management and resolve issues.

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ExampleExamples of trade studies are given in

O:\ENGR_LIB\DAR\DAR Training\Web-based DAR Course\dar_index.html

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Webster Tradeoff Study ReferencesUtility Curves (Trade-off Study) FM.05-994Evaluate Design Solutions RW.12.13.14A010Trade-off Study Matrix (template) FM.05-949

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Webster DAR ReferencesOrganizational Business Practices SP.12.15.02Perform Decision Analysis and Resolution OM.12.15.02A001

Perform Formal Evaluation RW.12.01.00A004RF.QM Tradeoff AnalysesRF.Decide Formal EvaluationRF.Guide Formal EvaluationsRF.Other DAR MethodsRF.Establish Evaluation CriteriaRF.ID Alternative SolutionsRF.Select Evaluation MethodsRF.Evaluate AlternativesRF.Select Preferred SolutionsRF.Expert Review of Trade off StudiesRF.Retention Formal DecisionsRF.Manage Improve DAR

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Documents

The Decision Analysis and Resolution (DAR) Process Terry Bahill Systems and Industrial Engineering University of Arizona [email protected] ©, 2005-09,