This Cost Estimates Software Development document shows how Eduardo Montes estimated the $238,000 base cost of the ProjectAdm SaaS platform using a combination of bottom-up estimating by WBS package and analogous cross-validation against the prior Phoenix project. This Excel workbook contains the detailed hour and cost breakdown for each team member across all 12 WBS packages — the granular input that underpins the Cost Baseline and the Basis of Estimates.

What Are Cost Estimates?

Cost Estimates are a PMBOK 8 output in the Planning Performance Domain that provide a quantitative assessment of the likely costs required to complete project work. They are calculated for all resources that will be charged to the project — human resources, equipment, materials, and services. Cost estimates are inputs to the Cost Baseline and the Basis of Estimates. PMBOK 8 recognizes multiple estimating methods (analogous, parametric, bottom-up, and three-point), and the accuracy of estimates improves as project scope is progressively elaborated. For software projects, cost estimates are primarily driven by labor hours, making accurate capacity planning and hourly rate assumptions critical.

What This Cost Estimates Software Development Includes

The ProjectAdm Cost Estimates workbook contains detailed labor and non-labor cost estimates:

• Labor Estimates by Team Member — Eduardo Montes (PM/SM): 560 hrs × $35/hr = $19,600; Henry Douglas (PO/Tech Lead): 448 hrs × $50/hr = $22,400; Marcus Webb (Sr. Backend): 1,680 hrs × $45/hr = $75,600; Julia Chen (Sr. Frontend): 1,120 hrs × $40/hr = $44,800; Bruno Silva (Fullstack): 1,120 hrs × $38/hr = $42,560; Camila Rocha (UI/UX): 560 hrs × $32/hr = $17,920; Lucas Park (QA): 336 hrs × $30/hr = $10,080; Total labor: $233,960
• Non-Labor Estimates — AWS infrastructure (development phase, 13.5 months): $16,200; External penetration test: $3,200; External Spanish translator: $800; Software licenses and tools: $840 (Notion Pro, GitHub Teams, Figma); Total non-labor: $21,040; less non-labor already in overhead: $17,000 credit → net additional non-labor: $4,040
• Estimation Method Notes — Bottom-up: all 12 WBS packages estimated at task level by responsible team member; Analogous: Marcus Webb backend rates cross-validated against Phoenix project actuals (variance: -3.2%); Parametric: Julia Chen frontend estimated at 420 LOC/day × 47,200 LOC ÷ 8 hrs/day = 1,100 hrs (rounded up to 1,120 for Safari buffer)
• Three-Point Estimates (High-Uncertainty Items) — AI Engine (WBS 1.10): Optimistic 580 hrs, Most Likely 720 hrs, Pessimistic 960 hrs; PERT estimate: (580+4×720+960)/6 = 723 hrs; used 720 hrs; QA overall: O=480, ML=560, P=720; PERT: 563 hrs; used 560 hrs
• Estimate Accuracy by Phase — Phase 1 (Architecture): ±10% (team has prior AWS experience); Phase 2 (MVP): ±12%; Phase 3 (SaaS Engine): ±15%; Phase 4 (Advanced Features, AI): ±20%; Phase 5 (Go-Live): ±8% (mostly known work)
• Estimate vs. Actuals at Closure — Total estimate: $238,000; Total actual: $230,900; variance: -3.0% (favorable); largest favorable variance: Marcus Webb backend $75,600 estimated vs. $72,800 actual (ISS-002 optimization was faster than expected post-Sprint 19); largest unfavorable: Julia Chen frontend $44,800 estimated vs. $46,200 actual (ISS-003 Safari rework +80hrs unplanned)

How Eduardo Montes Used This Cost Estimates Software Development

Eduardo Montes built the Cost Estimates Software Development workbook in Sprint 1 with input from every team member, who each estimated their own WBS package hours using Planning Poker adapted for cost estimation. Henry Douglas reviewed and approved all estimates for WBS packages under his technical domain. The estimate vs. actuals comparison at project closure showed the estimating process was accurate to within 3% — validating the bottom-up + analogous method for future ProjectAdm International software projects.

How to Use This Cost Estimates Software Development Document

When building your own Cost Estimates Software Development workbook, have team members estimate their own work rather than having the PM estimate on their behalf. The ProjectAdm approach produced more accurate estimates and also created accountability — team members who estimated their own hours were more committed to achieving them.

Download the Template and Deepen Your Knowledge

Ready to create your own cost estimates? Download the blank Cost Estimates Template (PMBOK 8).

• Download the Cost Estimates Template — PMBOK 8 (blank, ready to use)
• Read the full guide: Cost 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 Excel (.xlsx) | Project: Software Development (SaaS Platform) | PMBOK Edition: 8th (2025) | Domain: Planning