budget-variance-analyzer

# Budget Variance Analyzer ## Business Case ### Problem Statement Cost overruns surprise project teams: - Late detection of budget issues - No systematic variance analysis - Difficult to forecast final costs - Unclear root causes ### Solution Systematic budget variance analysis that tracks costs against budget, identifies trends, and forecasts final project costs. ### Business Value - **Early warning** - Detect overruns early - **Forecasting** - Predict final costs - **Accountability** - Track variance causes - **Decision support** - Informed cost decisions ## Technical Implementation ```python import pandas as pd from datetime import datetime, date from typing import Dict, Any, List, Optional, Tuple from dataclasses import dataclass, field from enum import Enum class VarianceStatus(Enum): """Variance status.""" UNDER_BUDGET = "under_budget" ON_BUDGET = "on_budget" OVER_BUDGET = "over_budget" CRITICAL = "critical" class CostCategory(Enum): """Cost categories.""" LABOR = "labor" MATERIAL = "material" EQUIPMENT = "equipment" SUBCONTRACTOR = "subcontractor" OVERHEAD = "overhead" CONTINGENCY = "contingency" OTHER = "other" class VarianceCause(Enum): """Common variance causes.""" SCOPE_CHANGE = "scope_change" QUANTITY_CHANGE = "quantity_change" PRICE_ESCALATION = "price_escalation" PRODUCTIVITY = "productivity" REWORK = "rework" DELAY = "delay" UNFORESEEN = "unforeseen" ESTIMATE_ERR...