Merrill -Myths Taboos & Inconvenient Truths (PLG June 2018) · 2018. 7. 13. · 1.Estimation Problem is real 2.Variable Scope might be a solution 3.The solution might not be acceptable

Warm-upIntroduce yourself to your neighbor.

Answer, “How do you produce, consume, or experience project or release-level estimates?”

Describe your feelings about the topic of estimation.

Robert T. MerrillSenior Business Analyst

Division of Information Technology (DoIT)IT Center of Excellence PMO

University of Wisconsin–Madison

Project EstimationMyths, Taboos, and Inconvenient Truths

NOTE:

Talk as presented

omitted about 1/3 of

this material.

Estimation TechniquesGuess: Many want to hear this

Managing Estimation RiskReality: Prepared talk is about this

Techniques

Compare with History• Qualitative—”feels like”

• Semi-Quantitative—”countables”

Break it down• Tasks

• Value

Task Breakdown“Nothing bigger than 4 h”

Good• There’s my work plan!• Did my last 2 ~80-hour engagements this way• Solid ground if tasks are recurringBad• Scales poorly• Brittle--scope change ripples• Missed tasks• Encourages negotiating of tasks

Value BreakdownValue outside the team—use or feedback

Good• Scales better• Scope is visible and negotiable• We needed a comprehensible scope anyway• Encourages good BA and UX workBad• A new skill• Still have to estimate the value chunks

User StoriesApplicationAs a PM, I can compute an actual-to-plan ratio and apply it to the rest of the plan, so that I’m encouraged to do this early and often.

InfrastructureAs an authorized user, I can connect securely and wirelessly to HRS in the 7100 room block of 21 N Park.

History: Subjective“It feels more like Project X than A or Z”

Good• Quick-acting antidote to Planning FallacyBad• Requires project history (doesn’t have to

be precise to be useful)• Can make people fearful• Open to gaming

History: Semi-Objective“2 lecture halls, 9 classrooms, 22 offices”

“5 data types, 4 forms, 9 reports”

Good• Even stronger antidote to Planning Fallacy• Strongly tied to scope; drives the right talksBad• Easy to fall in love (and analysis paralysis)• Almost an estimation specialist thing

What you get• Probably biased low

• Tasks either optimistic or padded

• More detail might be better

• More people involved might be better

The Estimation Problem1. Estimates are ranges

2. Ranges are larger than we think

3. Ranges cost more to reduce than we feel they should, or can afford

4. Ranges are too big to live with

A Learning Game• Non-competitive

• Two or three people

• Materials

1 page instructions

5 scoring grids, plus example

3 Features cards

1 die (six-side)

• Experiment!

Fixed scope, variable scope, lower budget

What did you see?1. Fixed-scope “busts” 35%-40%

2. Variable scope “busts” 1%-2%

3. Average score improves from ~0 to ~7

4. _

5. _

6. _

7. _

What I want you to hear1. Estimation Problem is real

2. Variable Scope might be a solution

3. The solution might not be acceptable

– Myths (feel-good stories, element of truth)

– Taboos (don’t even go there)

– Inconvenient Truths (feel-bad implications)

We’re Bad Estimators

Baseball−−−−What’s “Good?”

McConnell’s Cone

Reading the Cone

1000 h

4x1000=4000 h

0.25x1000=250 h

“Initial Concept” estimateExpect 16x range

Behind the Cone−−−−Scatter

2x

½x

Cone Caveats1. Not our shop, not our data

2. YMMV, and probably worse

3. Doesn’t converge if we’re dysfunctional

For every complex problemthere is an answer that isclear, simple, and wrong.

—H. L. Mencken

Clear, Simple, & Wrong

What We’ve Tried• Do better up-front work

• Fall back on crunch mode

• Treat plans as stretch goals

• Contingencies (Buffers, Pads)

• Late scope cuts

• #NoEstimates

The solution is properdefinition and planning

Cone Ranges and Costs

“Up Front”doesn’t equal “Instant and Free”

4x 2x

% of Project Cost

Estimate Range, low to

high

Buffer, % of 50/50 estimate

2-4% ~4x 100%

4-6% ~3x 70%

8-12% ~2x 40%

20-25% ~1.5x 20%

Cost of Accurate Estimates

The Estimation Problem

We can’t afford estimatesthat are accurate enoughto make estimation errorsa non-significant risk.

Inconvenient TruthInconvenient TruthInconvenient TruthInconvenient Truth





• Late scope cuts

• #NoEstimates

https://cs.stanford.edu/people/eroberts/cs201/projects/crunchmode/index.html





• Late scope cuts

• #NoEstimates


I don’t think it means…





• Late scope cuts

• #NoEstimates






• Late scope cuts

• #NoEstimates



I just need a rough estimate.I won’t hold you to it.—Pinocchio





• Late scope cuts

• #NoEstimates



Management has a legitimate need for estimates






• Late scope cuts

• #NoEstimates




The hard part is getting people to give up the illusion of control at the beginning. —”Uncle Bob” Martin

What to do• Expand the Vocabulary

• Put Uncertainty in its place--SCOPE

• Do better up-front work




• #NoEstimates

Requested datesaren’t estimates

Estimateshave probabilities

and/or ranges

Estimates aren’t commitments

What they ask for

Range and probabilitiesaround a request

What you agreeto try to make happen

Vocabulary• Request / Demand

• Estimate

• Commitment

Is it an estimate?• Project effort estimate is 3500 h

• Project effort has a 50% chance of being 3500 hours or less

• Project duration is estimatedat 6-8 months

• The 50%-90% chance project duration is 6-8 months

Yes

OK, but…

Yes

Avoiding Games & Drama• Vocabulary

• Awareness (“Thomsett estimation games”)https://www.cutter.com/article/double-dummy-spit-and-other-estimating-games-405811

• Hard Soft Skills

Dialogue

Boundaries

Negotiation

What if we putthe uncertainty

in the scope?

In the beginning…

In the beginning was the ship date, and the specification was without form, and void…--Inception 1:1

Scope: A Big Pile of Rocks

Which do you understand?

Where uncertainty really is

Project uncertaintyreally wants to be

in the scope.


We do this.We always scope projects to fit.

What if we putthe uncertainty

in the scopeand managed it there?

Managed variable scope? How?

• How did we do it in the dice game?

• How do we do it for real?

The Scope-Schedule Swap

(Valuebreakdown,

e.g. story countOr story points)


+ +++


+

But you said you COULD…

No, we DIDN’T say we COULDN’T

But you said you COULD…





+

I think I’m missing a chart.

Consider whiteboard.

1. Crazy big ranges

2. Don’t squeeze the goose

3. Up-front work can’t save you

4. Pad the scope

5. Do Phase Two right away

6. Included for free with agile

[email protected]

What to do?• Monitor! (requires Breakdown)

• Adjust, with a multiplier.

You never make it up later.

If the plan’s a week behind reality at the end of four weeks, multiply the whole plan by 4/3.

Having The Talk• It never gets better by waiting.

• Don’t panic. Prepare.

• If you’re going to slip, SLIP!

Don’t trade a bad promise for a

slightly less bad promise.

• Have other options besides

slipping (the rest of the talk)

Documents

Merrill -Myths Taboos & Inconvenient Truths (PLG June 2018) · 2018. 7. 13. · 1.Estimation Problem is real 2.Variable Scope might be a solution 3.The solution might not be acceptable