AVAILABLE FOR WEB, FLUTTER & QA PROJECTS
How to use this tool
1. Input Task Scope or Story Points
Enter total estimated engineering hours or agile story points.
2. Set Three-Point PERT Values
Specify Optimistic, Most Likely, and Pessimistic duration estimates.
3. Configure Team Velocity
Select the number of full-time developers and effective daily productive hours (typically 5-6 hrs/day).
4. Review Milestones & Buffer
Inspect Gantt-style milestone phase delivery dates with statistical confidence standard deviations.
Formula or logic used
PERT Three-Point Estimation & Standard Deviation
Project Evaluation and Review Technique (PERT) computes weighted expected duration $E$ and variance $\sigma$ to model delivery risk scientifically.
Expected Time: $E = \frac{O + 4M + P}{6}$ (where $O$ is Optimistic, $M$ is Most Likely, $P$ is Pessimistic)Standard Deviation: $\sigma = \frac{P - O}{6}$68% Confidence Range: $E \pm 1\sigma$; 95% Confidence Range: $E \pm 2\sigma$Calendar Duration: $\text{Days} = \frac{\text{Total Hours}}{\text{Developers} \times \text{Effective Hours/Day}}$
Examples
Example 1: SaaS Dashboard Feature Release
Provides stakeholders with a realistic delivery target that absorbs unexpected technical roadblocks.
Example 2: Full Website Redesign & Migration
Demonstrates why single-developer timelines must account for SEO migration risk.
Common use cases
Agile Sprint Capacity Planning
Translate user story backlogs into realistic two-week sprint allocations.
Stakeholder Deadline Commitments
Prevent burnout and over-promising by providing statistical confidence intervals to management.
Agency Fixed-Bid Scoping
Calculate contingency buffer budgets to protect fixed-price software delivery margins.
Critical Path Milestone Tracking
Sequence design, frontend, backend API, and QA phases without dependency bottlenecks.
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Frequently asked questions
What is PERT estimation in software development?
PERT (Program Evaluation and Review Technique) uses a weighted average of three estimates: Optimistic (best case), Most Likely (standard execution), and Pessimistic (severe hurdles), giving 4x weight to Most Likely to produce a statistically sound forecast.
Why should productive hours be capped at 5-6 hours per day?
Real software developers do not code for 8 hours consecutively. Code reviews, standup meetings, architecture discussions, and context switching reduce direct engineering time to 5-6 hours daily.
Does adding more developers cut project duration proportionally?
No. According to Brooks's Law ('Adding manpower to a late software project makes it later'), team communication overhead and onboarding curves mean adding developers provides diminishing returns on short projects.
What buffer percentage should be added for technical debt?
Industry standard practice recommends adding a 15% to 25% contingency buffer to account for unexpected third-party API changes, security patches, and edge-case bug fixing.
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