Programmatic risk management workshop (slides)

69
opyright © 2008, 2009, Lewis & Fowler Programmatic Risk Management: A “not so simple” introduction to the complex but critical process of building a “credible” schedule Workshop, Lewis & Fowler Team, Denver, Colorado October 6 th and October 14 th 2008 1 /69 rogrammatic Risk Management Work (Handbook)

description

An introduction to programmatic risk management.

Transcript of Programmatic risk management workshop (slides)

Page 1: Programmatic risk management workshop (slides)

Copyright © 2008, 2009, Lewis & Fowler

Programmatic Risk Management:

A “not so simple” introduction to the complex but critical process of building a “credible” schedule

Workshop, Lewis & Fowler Team, Denver, Colorado

October 6th and October 14th 2008

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Programmatic Risk Management Work (Handbook)

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Agenda

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Duration Topic

20 Minutes Risk Management in Five Easy Pieces

15 Minutes Basic Statistics for programmatic risk management

15 Minutes Monte Carlo Simulation (MCS) theory

20 Minutes Mechanics of MSFT Project and Risk+

15 Minutes Programmatic Risk Ranking

15 Minutes Building a Credible schedule

20 Minutes Conclusion

120 Minutes

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When we say “Risk Management” What do we really mean?

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Five Easy Pieces†:

The Essentials of Managing Programmatic Risk

Managing the risk to cost, schedule, and technical performance is the basis of a successful project management method.† With apologies to Carole Eastman and Bob Rafelson for their 1970 film staring Jack Nicholson

Risk in Five Easy Pieces4/69

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Hope is Not a Strategy

A Strategy is the plan to successfully complete the project

If the project’s success factors, the processes that deliver them, the alternatives when they fail, and the measurement of this success are not defined in meaningful ways for both the customer and managers of the project – Hope is the only strategy left.

When General Custer was completely surrounded, his chief scout asked, “General what's our strategy?” Custer replied, “The first thing we need to do is make a note to ourselves – never get in this situation again.”

Hope is not a strategy!

Risk in Five Easy Pieces5/69

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No Single Point Estimate can be correct without knowing the variance Single Point Estimates use sample data to

calculate a single value (a statistic) that serves as a "best guess" for an unknown (fixed or random) population parameter

Bayesian Inference is a statistical inference where evidence or observations are used to infer the probability that a hypothesis may be true

Identifying underlying statistical behavior of the cost and schedule parameters of the project is the first step in forecasting future behavior

Without this information and the model in which it is used any statements about cost, schedule and completion dates are a 50/50 guesses

When estimating cost and duration for planning purposes using Point Estimates results in the least likely result.

A result with a 50/50 chance of being true.

Risk in Five Easy Pieces6/69

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Without Integrating $, Time, and TPM you’re driving in the rearview mirror

Addressing customer satisfaction means incorporating product requirements and planned quality into the Performance Measurement Baseline to assure the true performance of the project is made visible.

Cost

($)

Schedule (t)

TechnicalPerformance (TPM)

Risk in Five Easy Pieces7/69

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Without a model for risk management, you’re driving in the dark with the headlights turn off

Risk Management means using a proven risk management process, adapting this to the project environment, and using this process for everyday decision making.

The Risk Management process to the right is used by the US DOD and differs from the PMI approach in how the processes areas are arranged.

The key is to understand the relationships between these areas.

Risk in Five Easy Pieces8/69

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Risk Communication is …

An interactive process of exchange of information and opinion among individuals, groups, and institutions; often involving multiple messages about the nature of risk or expressing concerns, opinions, or reactions to risk messages or to legal or institutional arrangements for risk management.

Bad news is not wine. It does not improve with age — Colin Powell

Risk in Five Easy Pieces9/69

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Basic Statistics for Programmatic Risk Management

Since all point estimates are wrong, statistical estimates will be needed to construct a credible cost and schedule model

Basic Statistics10/69

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Uncertainty and Risk are not the same thing – don’t confuse them Uncertainty stems from

unknown probability distributions– Requirements change impacts– Budget Perturbations– Re–work, and re–test

phenomena– Contractual arrangements

(contract type, prime/sub relationships, etc)

– Potential for disaster (labor troubles, shuttle loss, satellite “falls over”, war, hurricanes, etc.)

– Probability that if a discrete event occurs it will invoke a project delay

Risk stems from known probability distributions– Cost estimating methodology

risk resulting from improper models of cost

– Cost factors such as inflation, labor rates, labor rate burdens, etc

– Configuration risk (variation in the technical inputs)

– Schedule and technical risk coupling

– Correlation between risk distributions

Basic Statistics11/69

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There are 2 types of Uncertainty encountered in cost and schedule

Static uncertainty is natural variation and foreseen risks– Uncertainty about the value of a

parameter Dynamic uncertainty is unforeseen

uncertainty and “chaos”– Stochastic changes in the underlying

environment– System time delays, interactions between

the network elements, positive and negative feedback loops

– Internal dependencies Basic Statistics

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The Multiple Sources of Schedule Uncertainty and Sorting Them Out is the Role of Planning Unknown interactions drive

uncertainty Dynamic uncertainty can be

addressed by flexibility in the schedule– On ramps– Off ramps– Alternative paths– Schedule “crashing” opportunities

Modeling of this dynamic uncertainty requires simulation rather than static PERT based path assessment– Changes in critical path are

dependent on time and state of the network

– The result is a stochastic network

Basic Statistics13/69

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Statistics at a Glance

Probability distribution – A function that describes the probabilities of possible outcomes in a "sample space.”

Random variable – variable a function of the result of a statistical experiment in which each outcome has a definite probability of occurrence.

Determinism – a theory that phenomena are causally determined by preceding events or natural laws.

Standard deviation (sigma value) – An index that characterizes the dispersion among the values in a population.

Bias –The expected deviation of the expected value of a statistical estimate from the quantity it estimates.

Correlation – A measure of the joint impact of two variables upon each other that reflects the simultaneous variation of quantities.

Percentile – A value on a scale of 100 indicating the percent of a distribution that is equal to or below it.

Monte Carlo sampling – A modeling technique that employs random sampling to simulate a population being studied.

Basic Statistics14/69

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Statistics Versus Probability

In building a risk tolerant schedule, we’re interested in the probability of a successful outcome

– “What is the probability of making a desired completion date?”

But the underlying statistics of the tasks influence this probability

The statistics of the tasks, their arrangement in a network of tasks and correlation define how this probability based estimated developed.

Basic Statistics15/69

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Each path and each task along that path has a probability distribution

Any path could be critical depending on the convolution of the underlying task completion time probability distribution functions

The independence or dependency of each task with others in the network, greatly influences the outcome of the total project duration

Understanding this dependence is critical to assessing the credibility of the plan as well as the total completion time of that plan

Basic Statistics16/69

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Probability Distribution Functions are the Life Blood of good planning

Probability of occurrence as a function of the number of samples

“The number of times a task duration appears in a Monte Carlo simulation”

Basic Statistics17/69

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Statistics of a Triangle Distribution

Triangle distributions are useful when there is limited information about the characteristics of the random variables are all that is available.

This is common in project cost and schedule estimates.

Mode = 2000 hrs

Median = 3415 hrs

Mean = 3879 hrs

Minimum 1000 hrs

Maximum6830 hrs

50% of all possible values are under this area of the curve. This is the definition of the median

Basic Statistics18/69

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Basics of Monte Carlo Simulation

Far better an approximate answer to the right question, which is often vague, than an exact answer to the wrong question, which can always be made precise. — John W. Tukey, 1962

Basics of Monte Carlo19/69

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Monte Carlo Simulation

Yes Monte Carlo is named after the country full of casinos located on the French Rivera

Advantages of Monte Carlo over PERT is that Monte Carlo…– Examines all paths, not just the critical

path– Provides an accurate (true) estimate of

completion• Overall duration distribution • Confidence interval (accuracy range)

– Sensitivity analysis of interacting tasks– Varied activity distribution types – not restricted to Beta– Schedule logic can include branching – both probabilistic and conditional– When resource loaded schedules are used – provides integrated cost and schedule

probabilistic model

Basics of Monte Carlo20/69

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First let’s be convinced that PERT has limited usefulness

The original paper (Malcolm 1959) states– The method is “the best that could be done in a real

situation within tight time constraints.”– The time constraint was One Month

The PERT time made the assumption that the standard deviation was about 1/6 of the range (b–a), resulting in the PERT formula.

It has been shown that the PERT mean and standard deviation formulas are poor approximations for most Beta distributions (Keefer 1983 and Keefer 1993).– Errors up to 40% are possible for the PERT mean– Errors up to 550% are possible for the PERT

standard deviation

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Critical Path and Mostly Likelies

Critical Path’s are Deterministic– At least one path exists through

the network– The critical path is identified by

adding the “single point” estimates– The critical predicts the completion

date only if everything goes according to plan (we all know this of course)

Schedule execution is Probabilistic– There is a likelihood that some durations will comprise a path that is off the critical

path– The single number for the estimate – the “single point estimate” is in fact a most

likely estimate– The completion date is not the most likely date, but is a confidence interval in the

probability distribution function resulting from the convolution of all the distributions along all the paths to the completion of the project

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Deterministic PERT Uses Three Point Estimates In A Static Manner

Durations are defined as three point estimates– These estimates are very subjective if captured individually by asking…– “What is the Minimum, Maximum, and Most Likely”

Critical path is defined from these estimates is the algebraic addition of three point estimates

Project duration is based on the algebraic addition of the times along the critical path

This approach has some serious problems from the outset– Durations must be independent– Most likely is not the same as the

average

Basics of Monte Carlo23/69

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Foundation of Monte Carlo Theory

George Louis Leclerc, Comte de Buffon, asked what was the probability that the needle would fall across one of the lines, marked in green.

That outcome occurs only if: sinA l

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Mechanics of Risk+ integrated with Microsoft Project

Any credible schedule is a credible model of its dynamic behavior. This starts with a Monte Carlo model of the schedule’s network of tasks

Mechanics of Risk+25/69

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The Simplest Risk+ elements

Task to “watch”(Number3)

Most Likely(Duration3)

Pessimistic(Duration2)

Optimistic(Duration1)

Distribution(Number1)

Mechanics of Risk+26/69

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The output of Risk+

The height of each box indicates how often the project complete in a given interval during the run

The S–Curve shows the cumulative probability of completing on or before a given date.

The standard deviation of the completion date and the 95% confidence interval of the expected completion date are in the same units as the “most likely remaining duration” field in the schedule

Date: 9/26/2005 2:14:02 PMSamples: 500Unique ID: 10Name: Task 10

Completion Std Deviation: 4.83 days95% Confidence Interval: 0.42 daysEach bar represents 2 days

Completion Date

Fre

qu

en

cy

Cu

mu

lativ

e P

rob

ab

ility

3/1/062/10/06 3/17/06

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

0.02

0.04

0.06

0.08

0.10

0.12

0.14

0.16 Completion Probability Table

Prob ProbDate Date0.05 2/17/060.10 2/21/060.15 2/22/060.20 2/22/060.25 2/23/060.30 2/24/060.35 2/27/060.40 2/27/060.45 2/28/060.50 3/1/06

0.55 3/1/060.60 3/2/060.65 3/3/060.70 3/3/060.75 3/6/060.80 3/7/060.85 3/8/060.90 3/9/060.95 3/13/061.00 3/17/06

Task to “watch”

80% confidence that task will complete by 3/7/06

Mechanics of Risk+27/69

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A Well Formed Risk+ Schedule

For Risk+ to provide useful information, the underlying schedule must be well formed on some simple way.

Mechanics of Risk+28/69

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A Well formed Risk+ Schedule

A good critical path network– No constraint dates– Lowest level tasks have predecessors and

successors– 80% of relationships are finish to start

Identify risk tasks – These are “reporting tasks”– Identify the preview task to watch during

simulation runs

Defining the probability distribution profile for each task– Bulk assignment is an easy way to start– A – F ranking is another approach– Individual risk profile assignments is best but tedious

Mechanics of Risk+29/69

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Analyzing the Risk+ Simulation

Risk+ generates one or more of the following outputs:

– Earliest, expected, and latest completion date for each reporting task

– Graphical and tabular displays of the completion date distribution for each reporting task

– The standard deviation and confidence interval for the completion date distribution for each reporting task

– The criticality index (percentage of time on the critical path) for each task

– The duration mean and standard deviation for each task – Minimum, expected, and maximum cost for the total project – Graphical and tabular displays of cost distribution for the total project – The standard deviation and confidence interval for cost at the total project level

Mechanics of Risk+30/69

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Programmatic Risk Ranking

The variance in task duration must be defined in some systematic way. Capturing three point values is the least desirable.

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Thinking about risk ranking

These classifications can be used to avoid asking the “3 point” question for each task

This information will be maintained in the IMS When updates are made the percentage

change can be applied across all tasks

Classification Uncertainty Overrun

A Routine, been done before Low 0% to 2%

B Routine, but possible difficulties Medium to Low 2% to 5%

C Development, with little technical difficulty Medium 5% to 10%

D Development, but some technical difficulty Medium High 10% to 15%

E Significant effort, technical challenge High 15% to 25%

F No experience in this area Very High 25% to 50%

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Steps in characterizing uncertainty

Use an “envelope” method to characterize the minimum, maximum and “most likely”

Fit this data to a statistical distribution Use conservative assumptions Apply greater uncertainty to less mature

technologies Confirm analysis matches intuition

Remember Sir Francis Bacon’s quote about beginning with uncertainty and ending with certainty.

If we start with a what we think is a valid number we will tend to continue with that valid number.

When in fact we should speak only in terms of confidence intervals and probabilities of success.

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Sobering observations about 3 point estimates when asking engineers In 1979, Tversky and Kahneman proposed an alternative

to Utility theory. Prospect theory asserts that people make predictably irrational decisions.

The way that a choice of decisions is presented can sway a person to choose the less rational decision from a set of options.

Once a problem is clearly and reasonably presented, rarely does a person think outside the bounds of the frame.

Source:– “The Causes of Risk Taking By Project Managers,”

Proceedings of the Project Management Institute Annual Seminars & Symposium November 1–10, 2001 • Nashville, Tenn

– Tversky, Amos, and Daniel Kahneman. 1981. The Framing of Decisions and the Psychology of Choice. Science 211 (January 30): 453–458

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Building a Credible Schedule

A credible schedule contains a well formed network, explicit risk mitigations, proper margin for these risks, and a clear and concise critical path(s). All of this is prologue to analyzing the schedule.

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Good schedules have a contingency plans

The schedule contingency needed to make the plan credible can be derived from the Risk+ analysis

The schedule contingency is the amount of time added (or subtracted) from the baseline schedule necessary to achieve the desired probability of an under run or over run.

The schedule contingency can be determined through– Monte Carlo simulations (Risk+)– Best judgment from previous experience– Percentage factors based on historical experience– Correlation analysis for dependency impacts

Is This Our ContingencyPlan ?

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Schedule quality and accuracy

Accuracy range– Similar for each estimate class

Consistent with estimate– Level of project definition– Purpose– Preparation effort

Monte Carlo simulation– Analysis of results shows quality attained versus the quality sought

(expected accuracy ranges) Achieving specified accuracy requirements

– Select value at end points of confidence interval– Calculate percentages from base schedule completion date, including

the contingency

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Technical Performance Measures

Technical Performance Measures are one method of showing risk by done– Specific actions taken in the IMS to move the compliance forward toward the

goal

Activities that assessing the increasing compliance to the technical performance measure can be show in the IMS– These can be

Accomplishment Criteria

Building a Credible Schedule38/69

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The Monte Carlo Process starts with the 3 point estimates

Estimates of the task duration are still needed, just like they are in PERT– Three point estimates could be used– But risk ranking and algorithmic generation of the

“spreads” is a better approach

Duration estimates must be parametric rather than numeric values– A geometric scale of parametric risk is one approach

Branching probabilities need to be defined– Conditional paths through the schedule can be

evaluated using Monte Carlo tools– This also demonstrate explicit risk mitigation

planning to answer the question “what if this happens?”

These three point estimates are not the PERT ones.

They are derived from the ordinal risk ranking process.

This allows them to be “calibrated” for the domain, correlated with the technical risk model.

Building a Credible Schedule39/69

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Expert Judgment is required to build a Risk Management approach Expert judgment is typically the basis of cost and

schedule estimates– Expert judgment is usually the weakest area of process

and quantification– Translating from English (SOW) to mathematics

(probabilistic risk model) is usually inconsistent at best and erroneous at worst

One approach– Plan for the “best case” and preclude a self–fulfilling

prophesy– Budget for the “most likely” and recognize risks and

uncertainties– Protect for the “worst case” and acknowledge the

conceivable in the risk mitigation plan The credibility of the “best case” estimates if crucial to

the success of this approach

Building the variance values for the ordinal risk rank is a technical process, requiring engineering judgment.

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Guiding the Risk Factor Process requires careful weighting of each level of risk

For tasks marked “Low” a reasonable approach is to score the maximum 10% greater than the minimum.

The “Most Likely” is then scored as a geometric progression for the remaining categories with a common ratio of 1.5

Tasks marked “Very High” are bound at 200% of minimum.– No viable project manager would like a task

grow to three times the planned duration without intervention

The geometric progress is somewhat arbitrary but it should be used instead of a linear progression

Min Most Likely

Max

Low 1.0 1.04 1.10

Low+ 1.0 1.06 1.15

Moderate 1.0 1.09 1.24

Moderate+ 1.0 1.14 1.36

High 1.0 1.20 1.55

High+ 1.0 1.30 1.85

Very High 1.0 1.46 2.30

Very High+ 1.0 1.68 3.00

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Assume now we have a well formed schedule – now what?

With all the “bone head” elements removed, we can say we have a well formed schedule

But the real role of Planning is to forecast the future, provide alternative Plan’s for this forecast and actively engage all the participants in the projects in the Planning Process

For the role of PP&C is to move “reporting past performance” to “forecasting future performance” it must break the mold of using static models of cost and schedule

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We’re really after the management of schedule margin as part of planning

Plan the risk alternatives that “might” be needed

– Each mitigation has a Plan B branch

– Keep alternatives as simple as possible (maybe one task)

Assess probability of the alternative occurring

Assign duration and resource estimates to both branches

Turn off for alternative for a “success” path assessment

Turn off primary for a “failure” path assessment

30% Probabilityof failure

70% Probabilityof success

Plan B

Plan A Current Margin Future Margin

80% Confidence for completion with current margin

Duration of Plan B Plan A + Margin

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Successful margin management requires the reuse of unused durations

Programmatic Margin is added between Development, Production and Integration & Test phases

Risk Margin is added to the IMS where risk alternatives are identified

Margin that is not used in the IMS for risk mitigation will be moved to the next sequence of risk alternatives – This enables us to buy back schedule margin

for activities further downstream – This enables us to control the ripple effect of

schedule shifts on Margin activities

5 Days Margin

5 Days Margin

Plan B

Plan A

Plan B

Plan AFirst Identified Risk Alternative in IMS

Second Identified Risk Alternative in IMS

3 Days Margin Used

Downstream Activities shifted to left 2 days

Duration of Plan B < Plan A + Margin

2 days will be added to this margin task to bring schedule back on track

Building a Credible Schedule44/69

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Simulation Considerations

Schedule logic and constraints– Simplify logic – model only paths which, by

inspection, may have a significant bearing on the final result

– Correlate similar activities– No open ends– Use only finish–to–start relationships with no

lags– Model relationships other than finish–to–start

as activities with base durations equal to the lag value

– Eliminate all date constraints– Consider using branching for known

alternativesBuilding a Credible Schedule

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The contents of the schedule

Constraints Lead/Lag Task relationships Durations Network topology

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Simulation Considerations

Selection of Probability Distributions– Develop schedule simulation inputs

concurrently with the cost estimate• Early in process – use same subject matter

experts• Convert confidence intervals into probability

duration distributions

– Number of distributions vary depending on software

– Difficult to develop inputs required for distributions

– Beta and Lognormal better than triangular; avoid exclusive use of Normal distribution

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Sensitivity Analysis describes which tasks drive the completion times

Concentrates on inputs most likely to improve quality (accuracy)

Identifies most promising opportunities where additional work will help to narrow input ranges

Methods– Run multiple simulations– Use criticality index– “Tornado” or Pareto graph

Building a Credible Schedule48/69

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What we get in the end is a Credible Model of the schedule

Concept generator from Ramon Lull’s Ars Magna (C. 1300)

All models are wrong. Some models are useful.– George Box (1919 – )

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Conclusion

At this point there is too much information. Processing this information will take time, patience, and most of all practice with the tools and the results they produce.

Conclusion50/69

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Conclusions

Project schedule status must be assessed in terms of a critical path through the schedule network

Because the actual durations of each task in the network are uncertain (they are random variables following a probability distribution function), the project schedule duration must be modeled statistically

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Conclusions

Quality (accuracy) is measured at the end points of achieved confidence interval (suggest 80% level)

Simulation results depend on:– Accuracy and care taken with base

schedule logic– Use of subject matter experts to establish

inputs– Selection of appropriate distribution types– Through analysis of multiple critical paths– Understanding which activities and paths

have the greatest potential impact

Conclusion52/69

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Conclusions

Cost and schedule estimates are made up of many independent elements. – When each element is planned as best case – e.g. a

probability of achievement of 10% – The probability of achieving best case for a two–

element estimate is 1% – For three elements, 0.01%– For many elements, infinitesimal– In effect, it is zero.

In the beginning no attempt should be made to distinguish between risk and uncertainty– Risk involves uncertainty but it is indeed more– For initial purposes it is unimportant– The effect is combined into one statistical factor

called “risk,” which can be described by a single probability distribution function

Conclusion53/69

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What are we really after in the end?

As the program proceeds so does:– Increasing

accuracy– Reduced

schedule risk– Increasing

visual confirmation that success can be reached

Current Estimate Accuracy

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Points to remember

Good project management is good risk management

Risk management is how adults manage projects

The only thing we manage is project risk Risks impact objectives Risks come from the decisions we make while

trying to achieve the objectives Risks require a factual condition and have

potential negative consequences that must be mitigated in the schedule

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Usage is needed before understanding is acquired

Here and elsewhere, we shall not obtain the best insights into things until we actually see them growing from the beginning.

— Aristotle

Conclusion56/69

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The End

This is actually the beginning, since building a risk tolerant, credible, robust schedule requires constant “execution” of the plan.

A planning algorithm from Aristotle’s De Motu Animalium c. 400 BC

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Resources

1. “The Parameters of the Classical PERT: An Assessment of its Success,” Rafael Herrerias Pleguezuelo, http://www.cyta.com.ar/biblioteca/bddoc/bdlibros/pert_van/PARAMETROS.PDF

2. “Advanced Quantitative Schedule Risk Analysis,” David T. Hulett, Hulett & Associates, http://www.projectrisk.com/index.html

3. “Schedule Risk Analysis Simplified,” David T. Hulett, Hulett & Associates, http://www.projectrisk.com/index.html

4. “Project Risk Management: A Combined Analytical Hierarchy Process and Decision Tree Approach,” Prasanta Kumar Dey, Cost Engineering, Vol. 44, No. 3, March 2002.

5. “Adding Probability to Your ‘Swiss Army Knife’,” John C. Goodpasture, Proceedings of the 30th Annual Project Management Institute 1999 Seminars and Symposium, October, 1999.

6. “Modeling Uncertainty in Project Scheduling,” Patrick Leach, Proceedings of the 2005 Crystal Ball User Conference

7. “Near Critical Paths Create Violations in the PERT Assumptions of Normality,” Frank Pokladnik and Robert Hill, University of Houston, Clear Lake, http://www.sbaer.uca.edu/research/dsi/2003/procs/237–4203.pdf

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8. “Teaching SuPERT,” Kenneth R. MacLeod and Paul F. Petersen, Proceedings of the Decision Sciences 2003 Annual Meeting, Washington DC, http://www.sbaer.uca.edu/research/dsi/2003/by_track_paper.html

9. “The Beginning of the Monte Carlo Method,” N. Metropolis, Los Alamos Science, Special Issue, 1987. http://www.fas.org/sgp/othergov/doe/lanl/pubs/00326866.pdf

10. “Defining a Beta Distribution Function for Construction Simulation,” Javier Fente, Kraig Knutson, Cliff Schexnayder, Proceedings of the 1999 Winter Simulation Conference.

11. “The Basics of Monte Carlo Simulation: A Tutorial,” S. Kandaswamy, Proceedings of the Project Management Institute Annual Seminars & Symposium, November, 2001.

12. “The Mother of All Guesses: A User Friendly Guide to Statistical Estimation,” Francois Melese and David Rose, Armed Forces Comptroller, 1998, http://www.nps.navy.mil/drmi/graphics/StatGuide–web.pdf

13. “Inverse Statistical Estimation via Order Statistics: A Resolution of the Ill–Posed Inverse problem of PERT Scheduling,” William F. Pickard, Inverse Problems 20, pp. 1565–1581, 2004

Resources59/69

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14. “Schedule Risk Analysis: Why It Is Important and How to Do It, “Stephen A. Book, Proceedings of the Ground Systems Architecture Workshop (GSAW 2002), Aerospace Corporation, March 2002, http://sunset.usc.edu/GSAW/gsaw2002/s11a/book.pdf

15. “Evaluation of the Risk Analysis and Cost Management (RACM) Model,” Matthew S. Goldberg, Institute for Defense Analysis, 1998. http://www.thedacs.com/topics/earnedvalue/racm.pdf

16. “PERT Completion Times Revisited,” Fred E. Williams, School of Management, University of Michigan–Flint, July 2005, http://som.umflint.edu/yener/PERT%20Completion%20Revisited.htm

17. “Overcoming Project Risk: Lessons from the PERIL Database,” Tom Hendrick , Program Manager, Hewlett Packard, 2003, http://www.failureproofprojects.com/Risky.pdf

18. “The Heart of Risk Management: Teaching Project Teams to Combat Risk,” Bruce Chadbourne, 30th Annual Project Management Institute 1999 Seminara and Symposium, October 1999, http://www.risksig.com/Articles/pmi1999/rkalt01.pdf

Resources60/69

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20. Project Risk Management Resource List, NASA Headquarters Library, http://www.hq.nasa.gov/office/hqlibrary/ppm/ppm22.htm#art

21. “Quantify Risk to Manage Cost and Schedule,” Fred Raymond, Acquisition Quarterly, Spring 1999, http://www.dau.mil/pubs/arq/99arq/raymond.pdf

22. “Continuous Risk Management,” Cost Analysis Symposium, April 2005, http://www1.jsc.nasa.gov/bu2/conferences/NCAS2005/papers/5C_–_Cockrell_CRM_v1_0.ppt

23. “A Novel Extension of the Triangular Distribution and its Parameter Estimation,” J. Rene van Dorp and Samuel Kotz, The Statistician 51(1), pp. 63 – 79, 2002. http://www.seas.gwu.edu/~dorpjr/Publications/JournalPapers/TheStatistician2002.pdf

24. “Distribution of Modeling Dependence Cause by Common Risk Factors,” J. Rene van Dorp, European Safety and Reliability 2003 Conference Proceedings, March 2003, http://www.seas.gwu.edu/~dorpjr/Publications/ConferenceProceedings/Esrel2003.pdf

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25. “Improved Three Point Approximation To Distribution Functions For Application In Financial Decision Analysis,” Michele E. Pfund, Jennifer E. McNeill, John W. Fowler and Gerald T. Mackulak, Department of Industrial Engineering, Arizona State University, Tempe, Arizona, http://www.eas.asu.edu/ie/workingpaper/pdf/cdf_estimation_submission.pdf

26. “Analysis Of Resource–constrained Stochastic Project Networks Using Discrete–event Simulation,” Sucharith Vanguri, Masters Thesis, Mississippi State University, May 2005, http://sun.library.msstate.edu/ETD–db/theses/available/etd–04072005–123743/restricted/SucharithVanguriThesis.pdf

27. “Integrated Cost / Schedule Risk Analysis,” David T. Hulett and Bill Campbell, Fifth European Project Management Conference, June 2002.

28. “Risk Interrelation Management – Controlling the Snowball Effect,” Olli Kuismanen, Tuomo Saari and Jussi Vähäkylä, Fifth European Project Management Conference, June 2002.

29. The Lady Tasting Tea: How Statistics Revolutionized Science in the Twentieth Century, David Salsburg, W. H. Freeman, 2001

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30. “Triangular Approximations for Continuous Random Variables in Risk Analysis,” David G. Johnson, The Business School, Loughborough University, Liecestershire.

31. “Statistical Dependence through Common Risk Factors: With Applications in Uncertainty Analysis,” J. Rene van Dorp, European Journal of Operations Research, Volume 161(1), pp. 240–255.

32. “Statistical Dependence in the risk analysis for Project Networks Using Monte Carlo Methods,” J. Rene van Dorp and M. R. Dufy, International Journal of Production Economics, 58, pp. 17–29, 1999. http://www.seas.gwu.edu/~dorpjr/Publications/JournalPapers/Prodecon1999.pdf

33. “Risk Analysis for Large Engineering Projects: Modeling Cost Uncertainty for Ship Production Activities,” M. R. Dufy and J. Rene van Dorp, Journal of Engineering Valuation and Cost Analysis, Volume 2. pp. 285–301, http://www.seas.gwu.edu/~dorpjr/Publications/JournalPapers/EVCA1999.pdf

34. “Risk Based Decision Support techniques for Programs and Projects,” Barney Roberts and David Frost, Futron Risk Management Center of Excellence, http://www.futron.com/pdf/RBDSsupporttech.pdf

Resources63/69

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35. Probabilistic Risk Assessment Procedures Guide for NASA Managers and Practitioners, Office of Safety and Mission Assurance, April 2002. http://www.hq.nasa.gov/office/codeq/doctree/praguide.pdf

36. “Project Planning: Improved Approach Incorporating Uncertainty,” Vahid Khodakarami, Norman Fenton, and Martin Neil, Track 15 EURAM2005: “Reconciling Uncertainty and Responsibility” European Academy of Management. http://www.dcs.qmw.ac.uk/~norman/papers/project_planning_khodakerami.pdf

37. “A Distribution for Modeling Dependence Caused by Common Risk Factors,” J. Rene van Dorp, European Safety and Reliability 2003 Conference Proceedings, March 2003.

38. “Probabilistic PERT,” Arthur Nadas, IBM Journal of Research and Development, 23(3), May 1979, pp. 339–347.

39. “Ranked Nodes: A Simple and effective way to model qualitative in large–scale Bayesian Networks,” Norman Fenton and Martin Neil, Risk Assessment and Decision Analysis Research Group, Department of Computer Science, Queen Mary, University of London, February 21, 2005.

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40. “Quantify Risk to Manage Cost and Schedule,” Fred Raymond, Acquisition Review Quarterly, Spring 1999, pp. 147–154

41. “The Causes of Risk Taking by Project Managers,” Michael Wakshull, Proceedings of the Project Management Institute Annual Seminars & Symposium, November 2001.

42. “Stochastic Project Duration Analysis Using PERT–Beta Distributions,” Ron Davis.

43. “Triangular Approximation for Continuous Random Variables in Risk Analysis,” David G. Johnson, Decision Sciences Institute Proceedings 1998. http://www.sbaer.uca.edu/research/dsi/1998/Pdffiles/Papers/1114.pdf

44. “The Cause of Risk Taking by Managers,” Michael N.Wakshull, Proceedings of the Project Management Institute Annual Seminars & Symposium November 1–10, 2001, Nashville Tennessee , http://www.risksig.com/Articles/pmi2001/21261.pdf

45. “The Framing of Decisions and the Psychology of Choice,” Tversky, Amos, and Daniel Kahneman. 1981, Science 211 (January 30): 453–458, http://www.cs.umu.se/kurser/TDBC12/HT99/Tversky.html

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46. “Three Point Approximations for Continuous Random Variables,” Donald Keefer and Samuel Bodily, Management Science, 29(5), pp. 595 – 609.

47. “Better Estimation of PERT Activity Time Parameters,” Donald Keefer and William Verdini, Management Science, 39(9), pp. 1086 – 1091.

48. “The Benefits of Integrated, Quantitative Risk Management,” Barney B. Roberts, Futron Corporation, 12th Annual International Symposium of the International Council on Systems Engineering, July 1–5, 2001, http://www.futron.com/pdf/benefits_QuantIRM.pdf

49. “Sources of Schedule Risk in Complex Systems Development,” Tyson R. Browning, INCOSE Systems Engineering Journal, Volume 2, Issue 3, pp. 129 – 142, 14 September 1999, http://sbufaculty.tcu.edu/tbrowning/Publications/Browning%20(1999)––SE%20Sch%20Risk%20Drivers.pdf

50. “Sources of Performance Risk in Complex System Development,” Tyson R. Browning, 9th Annual International Symposium of INCOSE, June 1999, http://sbufaculty.tcu.edu/tbrowning/Publications/Browning%20(1999)––INCOSE%20Perf%20Risk%20Drivers.pdf

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51. “Experiences in Improving Risk Management Processes Using the Concepts of the Riskit Method,” Jyrki Konito, Gerhard Getto, and Dieter Landes, ACM SIGSOFT Software Engineering Notes , Proceedings of the 6th ACM SIGSOFT international symposium on Foundations of software engineering SIGSOFT '98/FSE-6,  Volume 23 Issue 6, November 1998.

52. “Anchoring and Adjustment in Software Estimation,” Jorge Aranda and Steve Easterbrook, Proceedings of the 10th European software engineering conference held jointly with 13th ACM SIGSOFT international symposium on Foundations of software engineering ESEC/FSE-13

53. “The Monte Carlo Method,” W. F. Bauer, Journal of the Society of Industrial Mathematics, Volume 6, Number 4, December 1958, http://www.cs.fsu.edu/~mascagni/Bauer_1959_Journal_SIAM.pdf.

54. “A Retrospective and Prospective Survey of the Monte Carlo Method,” John H. Molton, SIAM Journal, Volume 12, Number 1, January 1970, http://www.cs.fsu.edu/~mascagni/Halton_SIAM_Review_1970.pdf.

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