Operating model & engagement

Estimation and scope control

Compare methods, name the uncertainty and make the scope consequence explicit.

Current decision

36 person-weeks · PERT basis

Methods differ by 4 person-weeks. The original scope is selected.

Inspect the method assumptions, then stress the scope change.

Same instrument · 3 industries choosing a scenario replaces its inputs; save or share your current changes first

Scope change receipt

Effort: 36 → 36 person-weeks

Schedule: 8 → 8 weeks

Absorbed margin: 38.0% → 38.0%

No change is applied. Switch on the scope change below to compare its cost, schedule and margin before accepting it.

Estimation methods on the same original scope

Estimation methods on the same original scope
Method	Person-weeks	Difference from selected basis
bottomup	33	−3
analogous	32	−4
PERT mean	36	0

PERT uncertainty and method disagreement are different signals. The selected method sets the base; the scope receipt adds the same defined work package.

The three disagree by 4 weeks

That spread is the conversation. The analogous number is cheapest and most wrong; bottom up misses the unknowns it hasn't imagined; PERT's range is the honest answer, 32 to 40 weeks.

Confidence ladderP50 36wP80 39w · commitP90 41wThe mean is a coin flip; a defensible commit carries contingency to P80.

Staffing & schedule · from PERT

Engagement lead×1

Senior engineer×2

ML engineer×1

Data engineer×1

QA / eval×1

Effort 36wDuration ~8wkTeam 6

Change control

Add 2 dispute categories + a new data source, +12w, concentrated in data + eval.

Baseline

38%

Absorbed

38%

With change order

38%

If you act on this · the call → expected lift → how you'd measure it

The call

Commit to a confidence backed estimate and route material scope change through explicit control.

Expected lift · illustrative

Reduces margin leakage and delivery surprises by pricing uncertainty instead of hiding it.

How you'd measure it

P80 estimate, schedule variance, margin impact, change order value, scope movement.

Steering committee takeaway: AI estimates often break in data discovery and evaluation. Price those unknowns as line items or absorb them later.

Resume echo, consulting delivery estimation across HCLTech/Genpact/Deloitte.

How this is built

Bottom up = sum of a WBS with AI specific line items flagged. Analogous = past baseline × complexity factor. PERT = (O + 4M + P)/6 with ±(P−O)/6 as the range.

Duration = effort ÷ effective team capacity (4.8 FTE-weeks/week); margin = (revenue − cost)/revenue at $12k bill / $7.5k cost per person-week. A scope change absorbed silently drops margin; a change order re-prices it.

Stack: Next.js (static) + shared design system; client side only.

Limitations: this is a portfolio estimation model. Real estimation would require delivery history, client scope, technical discovery, staffing rates, vendor constraints, and commercial review.

Method, evidence and limitations

Prefer to read? The two minute case study · problem → approach → metric → outcome

Problem

A single point estimate can create false confidence. Senior delivery requires a range, a confidence level, a clear commitment point, and a disciplined approach to scope change.

Approach

The studio compares bottom up, analogous, and PERT estimates, then models staffing, schedule, confidence levels, and change control impact.

Why this way

This connects estimation to delivery confidence, margin protection, client expectation management, and commercial governance.

The metric

The P80 commit; gross margin under a scope change.

The trade-off

Absorbing scope silently protects the relationship but drops margin; a change order holds margin but is a harder conversation.

Outcome

A defensible committed estimate plus the change control impact of moving scope.