This Basis of Estimates Software Development document shows how Eduardo Montes documented the rationale behind every cost and duration estimate produced for ProjectAdm — a SaaS project management platform developed by ProjectAdm International from January 15, 2025 to February 28, 2026. Rather than presenting raw numbers alone, this output explains how each estimate was derived, what assumptions underpinned it, and what range of confidence applies, giving stakeholders the transparency they need to evaluate and approve the $280,000 project budget.

What Is a Basis of Estimates?

A Basis of Estimates is a PMBOK 8 output from the Planning Performance Domain that documents the supporting detail behind project cost and duration estimates. It explains the estimating method used (analogous, parametric, bottom-up, or three-point), the data sources consulted, the assumptions and constraints that shaped each figure, and the confidence range applied. Without a solid Basis of Estimates, a budget or schedule is just a number — with it, decision-makers can assess credibility, compare scenarios, and understand what could cause estimates to change.

What This Basis of Estimates Software Development Includes

This completed example covers the full estimating rationale for all major cost and schedule components of the ProjectAdm platform:

• Estimating Method per WBS Package — Bottom-up estimating used for all 12 WBS packages; analogous estimating cross-validated against a prior PHP/CodeIgniter project (Phoenix) completed by the same team in 2024
• Backend Development Estimate — Marcus Webb (Senior Backend): 1,680 hours at $45/hr = $75,600; based on 65 controllers and 50 models at an average of 12.5 hours per controller/model pair, validated against Phoenix actuals
• Frontend Development Estimate — Julia Chen (Senior Frontend): 1,120 hours at $40/hr = $44,800; parametric rate of 420 LOC/day applied to 47,200 lines of HTML/CSS/JS; Safari drag-drop complexity added 80-hour buffer (ISS-003)
• QA and Testing Estimate — Lucas Park (QA): 560 hours at $35/hr = $19,600; three-point estimate (O=480h, ML=560h, P=720h) using PERT formula; 321 PHPUnit tests at average 1.75h each including setup and integration
• Infrastructure and DevOps — AWS multi-region setup estimated at $18,400 using vendor quotes from AWS Pricing Calculator; Nginx configuration and CI/CD pipeline estimated at 120 hours (Henry Douglas + Marcus Webb)
• Contingency Reserve Basis — 15% ($42,000) applied to $238,000 base; derived from Monte Carlo simulation across 1,000 iterations showing P80 overrun at 14.8%; rounded to 15% per ProjectAdm International policy
• Schedule Duration Basis — 28 two-week sprints (56 weeks) from Jan 15, 2025 to Feb 28, 2026; velocity calibrated at 40 story points/sprint from Phoenix project; initial backlog sized at 1,092 story points across 5 epics
• Confidence Ranges — Phase 1 (Architecture, Sprints 1–4): ±10%; Phase 2–3 (MVP + SaaS Engine, Sprints 5–16): ±15%; Phase 4–5 (Advanced Features + Go-Live, Sprints 17–28): ±20% due to scope uncertainty in AI features
• Assumptions and Exclusions — Assumes team availability at 80% (accounting for meetings, PTO, and overhead); excludes post-launch hypercare beyond 30 days; third-party API costs (Stripe, PayPal) treated as pass-through

How Eduardo Montes Used This Basis of Estimates Software Development

Eduardo Montes presented this Basis of Estimates Software Development document to the ProjectAdm International steering committee during the M1 milestone review on January 31, 2025, alongside the Cost Baseline and Schedule Baseline. Henry Douglas, as co-sponsor and Product Owner, used the confidence ranges to negotiate the scope of the AI suggestion engine feature — ultimately agreeing to defer full AI integration to Sprint 20 based on the ±20% uncertainty range flagged in the estimates. When CR-002 (Gantt chart addition, +$4,500) was submitted in Sprint 8, the existing Basis of Estimates provided the benchmark for evaluating the change impact: Marcus Webb's parametric rate of 12.5 hours per controller confirmed the Gantt chart would require approximately 90 hours of backend work, aligning with the change request cost.

The document also served as an audit trail during Sprint 14 when ISS-002 (MariaDB performance on large boards) caused a 3-sprint delay in the advanced filtering feature. Because the original estimate documented the assumption of sub-500ms query response times, the team could formally record the variance and update the schedule baseline without renegotiating the entire project budget.

How to Use This Basis of Estimates Software Development Document

Use this example to understand how to connect every line item in your budget and schedule to a specific method, data source, and assumption. Notice that the ProjectAdm Basis of Estimates does not simply list hours — it explains why those hours were chosen, what historical data supported the estimate, and under what conditions the number could change. This transparency is what makes an estimate defensible in front of sponsors and clients.

When adapting this to your own Basis of Estimates Software Development project, focus first on identifying which packages have high uncertainty and document wider confidence ranges there. Low-uncertainty packages with historical benchmarks (like well-understood CRUD controllers) can carry tighter ranges, while novel features (AI integrations, new payment gateways) should carry explicit risk buffers with documented rationale.

Download the Template and Deepen Your Knowledge

Ready to create your own basis of estimates? Download the blank Basis of Estimates Template (PMBOK 8).

• Download the Basis of Estimates Template — PMBOK 8 (blank, ready to use)
• Read the full guide: Basis of Estimates in PMBOK 8

Want to go deeper? The PMBOK Guide 8th Edition is the definitive reference for modern project management. Get your copy and use it alongside these examples to build a solid, practical understanding of every performance domain.

Format: Microsoft Word (.docx) | Project: Software Development (SaaS Platform) | PMBOK Edition: 8th (2025) | Domain: Planning