Effort Estimation¶

The effort package provides types for estimating implementation effort and tracking complexity factors.

Overview¶

Effort estimation combines:

Person-days estimate - Numeric effort in person-days
T-shirt sizing - Quick categorical sizing (XS, S, M, L, XL)
Confidence levels - How certain the estimate is
Complexity factors - What makes implementation complex

EffortEstimate Type¶

type EffortEstimate struct {
    PersonDays int        `json:"person_days"`
    TShirtSize TShirtSize `json:"tshirt_size,omitempty"`
    Confidence Confidence `json:"confidence"`
    Note       string     `json:"note,omitempty"`
}

T-Shirt Sizing¶

Quick categorical sizing for rough estimates:

Size	Description	Typical Days
`XS`	Extra Small	1-2 days
`S`	Small	3-5 days
`M`	Medium	1-2 weeks
`L`	Large	2-4 weeks
`XL`	Extra Large	4+ weeks

import "github.com/grokify/prism-roadmap/effort"

size := effort.TShirtSizeMedium
days := size.EstimatedDays() // Returns 7-10

Confidence Levels¶

Indicate certainty of estimates:

Level	Multiplier	When to Use
`high`	1.0	Well-understood work, similar past projects
`medium`	1.3	Some unknowns, reasonable assumptions
`low`	1.5	Many unknowns, exploratory work

conf := effort.ConfidenceMedium
multiplier := conf.Multiplier() // Returns 1.3

Quick Start¶

import "github.com/grokify/prism-roadmap/effort"

estimate := &effort.EffortEstimate{
    PersonDays: 15,
    TShirtSize: effort.TShirtSizeMedium,
    Confidence: effort.ConfidenceMedium,
    Note:       "Includes API and UI work",
}

// Get adjusted estimate with confidence buffer
adjusted := estimate.AdjustedDays()
// 15 × 1.3 = 19.5 days

ComplexityFactors Type¶

Track what makes implementation complex:

type ComplexityFactors struct {
    NewArchitecture bool         `json:"new_architecture"`
    NewDesignUX     bool         `json:"new_design_ux"`
    NewBillingSKU   bool         `json:"new_billing_sku"`
    Dependencies    []Dependency `json:"dependencies,omitempty"`
}

type Dependency struct {
    ID          string `json:"id"`
    Name        string `json:"name"`
    Type        string `json:"type"`  // internal, external, vendor
    Team        string `json:"team,omitempty"`
    Status      string `json:"status"` // unknown, in_progress, blocked, complete
    RiskLevel   string `json:"risk_level,omitempty"`
    Description string `json:"description,omitempty"`
}

Complexity Score¶

Calculate overall complexity:

complexity := &effort.ComplexityFactors{
    NewArchitecture: true,  // +0.3
    NewDesignUX:     true,  // +0.2
    NewBillingSKU:   false, // +0.0
    Dependencies: []effort.Dependency{
        {Name: "Auth Service", Type: "internal"},
        {Name: "Payment Provider", Type: "vendor"},
    },
}

score := complexity.ComplexityScore()
// 1.0 (base) + 0.3 + 0.2 + (2 × 0.1) = 1.7

Complexity Weights¶

Factor	Weight	Description
Base	1.0	Starting score
New Architecture	+0.3	Major architectural changes
New Design/UX	+0.2	Design collaboration required
New Billing SKU	+0.2	Revenue/billing changes
Per Dependency	+0.1	Each external dependency

Dependency Types¶

Type	Description	Risk Level
`internal`	Another internal team	Lower
`external`	External API/service	Medium
`vendor`	Third-party vendor	Higher

Integration with RoadmapItem¶

import (
    "github.com/grokify/prism-roadmap/rmi"
    "github.com/grokify/prism-roadmap/effort"
)

item := &rmi.RoadmapItem{
    ID:   "feature-1",
    Name: "Payment Integration",
    Effort: &effort.EffortEstimate{
        PersonDays: 20,
        TShirtSize: effort.TShirtSizeLarge,
        Confidence: effort.ConfidenceLow,
    },
    Complexity: &effort.ComplexityFactors{
        NewArchitecture: false,
        NewBillingSKU:   true,
        Dependencies: []effort.Dependency{
            {Name: "Stripe API", Type: "vendor", Status: "unknown"},
        },
    },
}

// Priority considers effort in denominator
score := item.PriorityScore()

Best Practices¶

Estimation Tips

Use T-shirt sizes for initial roadmap discussions
Add person-day estimates when planning sprints
Lower confidence = higher buffer needed
Track dependencies early to identify risks

Common Pitfalls

Don't ignore complexity factors when estimating
Vendor dependencies often take longer than expected
New architecture work compounds effort
Update confidence as you learn more