Files
claude-skills-reference/finance/financial-analyst/scripts/forecast_builder.py
Alireza Rezvani eef020c9e0 feat(skills): add 5 new skills via factory methodology (#176)
Build campaign-analytics, financial-analyst, customer-success-manager,
sales-engineer, and revenue-operations skills using the Claude Skills
Factory workflow. Each skill includes SKILL.md, Python CLI tools,
reference guides, and asset templates. All 16 Python scripts use
standard library only with --format json/text support.

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
2026-02-06 23:51:58 +01:00

495 lines
19 KiB
Python

#!/usr/bin/env python3
"""
Forecast Builder
Driver-based revenue forecasting with 13-week rolling cash flow projection,
scenario modeling (base/bull/bear), and trend analysis using simple linear
regression (standard library only).
Usage:
python forecast_builder.py forecast_data.json
python forecast_builder.py forecast_data.json --format json
python forecast_builder.py forecast_data.json --scenarios base,bull,bear
"""
import argparse
import json
import math
import sys
from statistics import mean
from typing import Any, Dict, List, Optional, Tuple
def safe_divide(numerator: float, denominator: float, default: float = 0.0) -> float:
"""Safely divide two numbers, returning default if denominator is zero."""
if denominator == 0 or denominator is None:
return default
return numerator / denominator
def simple_linear_regression(
x_values: List[float], y_values: List[float]
) -> Tuple[float, float, float]:
"""
Simple linear regression using standard library.
Returns (slope, intercept, r_squared).
"""
n = len(x_values)
if n < 2 or n != len(y_values):
return (0.0, 0.0, 0.0)
x_mean = mean(x_values)
y_mean = mean(y_values)
ss_xy = sum((x - x_mean) * (y - y_mean) for x, y in zip(x_values, y_values))
ss_xx = sum((x - x_mean) ** 2 for x in x_values)
ss_yy = sum((y - y_mean) ** 2 for y in y_values)
slope = safe_divide(ss_xy, ss_xx)
intercept = y_mean - slope * x_mean
# R-squared
r_squared = safe_divide(ss_xy ** 2, ss_xx * ss_yy) if ss_yy > 0 else 0.0
return (slope, intercept, r_squared)
class ForecastBuilder:
"""Driver-based revenue forecasting with scenario modeling."""
def __init__(self, data: Dict[str, Any]) -> None:
"""Initialize the forecast builder."""
self.historical: List[Dict[str, Any]] = data.get("historical_periods", [])
self.drivers: Dict[str, Any] = data.get("drivers", {})
self.assumptions: Dict[str, Any] = data.get("assumptions", {})
self.cash_flow_inputs: Dict[str, Any] = data.get("cash_flow_inputs", {})
self.scenarios_config: Dict[str, Any] = data.get("scenarios", {})
self.forecast_periods: int = data.get("forecast_periods", 12)
def analyze_trends(self) -> Dict[str, Any]:
"""Analyze historical trends using linear regression."""
if not self.historical:
return {"error": "No historical data available"}
# Extract revenue series
revenues = [p.get("revenue", 0) for p in self.historical]
periods = list(range(1, len(revenues) + 1))
slope, intercept, r_squared = simple_linear_regression(
[float(x) for x in periods],
[float(y) for y in revenues],
)
# Calculate growth rates
growth_rates = []
for i in range(1, len(revenues)):
if revenues[i - 1] > 0:
growth = (revenues[i] - revenues[i - 1]) / revenues[i - 1]
growth_rates.append(growth)
avg_growth = mean(growth_rates) if growth_rates else 0.0
# Seasonality detection (if enough data)
seasonality_index: List[float] = []
if len(revenues) >= 4:
overall_avg = mean(revenues)
if overall_avg > 0:
seasonality_index = [r / overall_avg for r in revenues[-4:]]
return {
"trend": {
"slope": round(slope, 2),
"intercept": round(intercept, 2),
"r_squared": round(r_squared, 4),
"direction": "upward" if slope > 0 else "downward" if slope < 0 else "flat",
},
"growth_rates": [round(g, 4) for g in growth_rates],
"average_growth_rate": round(avg_growth, 4),
"seasonality_index": [round(s, 4) for s in seasonality_index],
"historical_revenues": revenues,
}
def build_driver_based_forecast(
self, scenario: str = "base"
) -> Dict[str, Any]:
"""
Build a driver-based revenue forecast.
Drivers may include: units, price, customers, ARPU, conversion rate, etc.
"""
scenario_adjustments = self.scenarios_config.get(scenario, {})
growth_adjustment = scenario_adjustments.get("growth_adjustment", 0.0)
margin_adjustment = scenario_adjustments.get("margin_adjustment", 0.0)
base_revenue = 0.0
if self.historical:
base_revenue = self.historical[-1].get("revenue", 0)
# Driver-based calculation
unit_drivers = self.drivers.get("units", {})
price_drivers = self.drivers.get("pricing", {})
customer_drivers = self.drivers.get("customers", {})
base_growth = self.assumptions.get("revenue_growth_rate", 0.05)
adjusted_growth = base_growth + growth_adjustment
base_margin = self.assumptions.get("gross_margin", 0.40)
adjusted_margin = base_margin + margin_adjustment
cogs_pct = 1.0 - adjusted_margin
opex_pct = self.assumptions.get("opex_pct_revenue", 0.25)
forecast_periods: List[Dict[str, Any]] = []
current_revenue = base_revenue
# If we have unit and price drivers, use them
has_unit_drivers = bool(unit_drivers) and bool(price_drivers)
if has_unit_drivers:
base_units = unit_drivers.get("base_units", 1000)
unit_growth = unit_drivers.get("growth_rate", 0.03) + growth_adjustment
base_price = price_drivers.get("base_price", 100)
price_growth = price_drivers.get("annual_increase", 0.02)
current_units = base_units
current_price = base_price
for period in range(1, self.forecast_periods + 1):
current_units = current_units * (1 + unit_growth / 12)
if period % 12 == 0:
current_price = current_price * (1 + price_growth)
period_revenue = current_units * current_price
cogs = period_revenue * cogs_pct
gross_profit = period_revenue - cogs
opex = period_revenue * opex_pct
operating_income = gross_profit - opex
forecast_periods.append({
"period": period,
"revenue": round(period_revenue, 2),
"units": round(current_units, 0),
"price": round(current_price, 2),
"cogs": round(cogs, 2),
"gross_profit": round(gross_profit, 2),
"gross_margin": round(adjusted_margin, 4),
"opex": round(opex, 2),
"operating_income": round(operating_income, 2),
})
else:
# Simple growth-based forecast
monthly_growth = (1 + adjusted_growth) ** (1 / 12) - 1
for period in range(1, self.forecast_periods + 1):
current_revenue = current_revenue * (1 + monthly_growth)
cogs = current_revenue * cogs_pct
gross_profit = current_revenue - cogs
opex = current_revenue * opex_pct
operating_income = gross_profit - opex
forecast_periods.append({
"period": period,
"revenue": round(current_revenue, 2),
"cogs": round(cogs, 2),
"gross_profit": round(gross_profit, 2),
"gross_margin": round(adjusted_margin, 4),
"opex": round(opex, 2),
"operating_income": round(operating_income, 2),
})
total_revenue = sum(p["revenue"] for p in forecast_periods)
total_operating_income = sum(p["operating_income"] for p in forecast_periods)
return {
"scenario": scenario,
"growth_rate": round(adjusted_growth, 4),
"gross_margin": round(adjusted_margin, 4),
"forecast_periods": forecast_periods,
"total_revenue": round(total_revenue, 2),
"total_operating_income": round(total_operating_income, 2),
"average_monthly_revenue": round(
safe_divide(total_revenue, len(forecast_periods)), 2
),
}
def build_rolling_cash_flow(self, weeks: int = 13) -> Dict[str, Any]:
"""Build a 13-week rolling cash flow projection."""
cfi = self.cash_flow_inputs
opening_balance = cfi.get("opening_cash_balance", 0)
weekly_revenue = cfi.get("weekly_revenue", 0)
collection_rate = cfi.get("collection_rate", 0.85)
collection_lag_weeks = cfi.get("collection_lag_weeks", 2)
# Weekly expenses
weekly_payroll = cfi.get("weekly_payroll", 0)
weekly_rent = cfi.get("weekly_rent", 0)
weekly_operating = cfi.get("weekly_operating", 0)
weekly_other = cfi.get("weekly_other", 0)
total_weekly_expenses = weekly_payroll + weekly_rent + weekly_operating + weekly_other
# One-time items
one_time_items: List[Dict[str, Any]] = cfi.get("one_time_items", [])
weekly_projections: List[Dict[str, Any]] = []
running_balance = opening_balance
# Revenue pipeline for lagged collections
revenue_pipeline: List[float] = [0.0] * collection_lag_weeks
for week in range(1, weeks + 1):
# Revenue collections (lagged)
revenue_pipeline.append(weekly_revenue)
collections = revenue_pipeline.pop(0) * collection_rate
# One-time items for this week
one_time_inflows = 0.0
one_time_outflows = 0.0
one_time_labels: List[str] = []
for item in one_time_items:
if item.get("week") == week:
amount = item.get("amount", 0)
if amount > 0:
one_time_inflows += amount
else:
one_time_outflows += abs(amount)
one_time_labels.append(item.get("description", ""))
total_inflows = collections + one_time_inflows
total_outflows = total_weekly_expenses + one_time_outflows
net_cash_flow = total_inflows - total_outflows
running_balance += net_cash_flow
weekly_projections.append({
"week": week,
"collections": round(collections, 2),
"one_time_inflows": round(one_time_inflows, 2),
"total_inflows": round(total_inflows, 2),
"payroll": round(weekly_payroll, 2),
"rent": round(weekly_rent, 2),
"operating": round(weekly_operating, 2),
"other_expenses": round(weekly_other, 2),
"one_time_outflows": round(one_time_outflows, 2),
"total_outflows": round(total_outflows, 2),
"net_cash_flow": round(net_cash_flow, 2),
"closing_balance": round(running_balance, 2),
"notes": ", ".join(one_time_labels) if one_time_labels else "",
})
# Summary
total_inflows = sum(w["total_inflows"] for w in weekly_projections)
total_outflows = sum(w["total_outflows"] for w in weekly_projections)
min_balance = min(w["closing_balance"] for w in weekly_projections)
min_balance_week = next(
w["week"]
for w in weekly_projections
if w["closing_balance"] == min_balance
)
return {
"weeks": weeks,
"opening_balance": opening_balance,
"closing_balance": round(running_balance, 2),
"total_inflows": round(total_inflows, 2),
"total_outflows": round(total_outflows, 2),
"net_change": round(total_inflows - total_outflows, 2),
"minimum_balance": round(min_balance, 2),
"minimum_balance_week": min_balance_week,
"cash_runway_weeks": (
round(safe_divide(running_balance, total_weekly_expenses))
if total_weekly_expenses > 0
else None
),
"weekly_projections": weekly_projections,
}
def build_scenario_comparison(
self, scenarios: Optional[List[str]] = None
) -> Dict[str, Any]:
"""Build and compare multiple scenarios."""
if scenarios is None:
scenarios = ["base", "bull", "bear"]
scenario_results: Dict[str, Any] = {}
for scenario in scenarios:
scenario_results[scenario] = self.build_driver_based_forecast(scenario)
# Comparison summary
comparison: List[Dict[str, Any]] = []
for scenario in scenarios:
result = scenario_results[scenario]
comparison.append({
"scenario": scenario,
"total_revenue": result["total_revenue"],
"total_operating_income": result["total_operating_income"],
"growth_rate": result["growth_rate"],
"gross_margin": result["gross_margin"],
"avg_monthly_revenue": result["average_monthly_revenue"],
})
return {
"scenarios": scenario_results,
"comparison": comparison,
}
def run_full_forecast(
self, scenarios: Optional[List[str]] = None
) -> Dict[str, Any]:
"""Run the complete forecast analysis."""
trends = self.analyze_trends()
scenario_comparison = self.build_scenario_comparison(scenarios)
cash_flow = self.build_rolling_cash_flow()
return {
"trend_analysis": trends,
"scenario_comparison": scenario_comparison,
"rolling_cash_flow": cash_flow,
}
def format_text(self, results: Dict[str, Any]) -> str:
"""Format forecast results as human-readable text."""
lines: List[str] = []
lines.append("=" * 70)
lines.append("FINANCIAL FORECAST REPORT")
lines.append("=" * 70)
def fmt_money(val: float) -> str:
if abs(val) >= 1e9:
return f"${val / 1e9:,.2f}B"
if abs(val) >= 1e6:
return f"${val / 1e6:,.2f}M"
if abs(val) >= 1e3:
return f"${val / 1e3:,.1f}K"
return f"${val:,.2f}"
# Trend Analysis
trend = results["trend_analysis"]
if "error" not in trend:
lines.append(f"\n--- TREND ANALYSIS ---")
t = trend["trend"]
lines.append(f" Direction: {t['direction']}")
lines.append(f" R-squared: {t['r_squared']:.4f}")
lines.append(
f" Average Historical Growth: "
f"{trend['average_growth_rate'] * 100:.1f}%"
)
if trend["seasonality_index"]:
lines.append(
f" Seasonality Index (last 4): "
f"{', '.join(f'{s:.2f}' for s in trend['seasonality_index'])}"
)
# Scenario Comparison
comp = results["scenario_comparison"]["comparison"]
lines.append(f"\n--- SCENARIO COMPARISON ---")
lines.append(
f" {'Scenario':<10s} {'Revenue':>14s} {'Op. Income':>14s} "
f"{'Growth':>8s} {'Margin':>8s}"
)
lines.append(" " + "-" * 62)
for c in comp:
lines.append(
f" {c['scenario']:<10s} {fmt_money(c['total_revenue']):>14s} "
f"{fmt_money(c['total_operating_income']):>14s} "
f"{c['growth_rate'] * 100:>7.1f}% "
f"{c['gross_margin'] * 100:>7.1f}%"
)
# Base scenario detail
base = results["scenario_comparison"]["scenarios"].get("base", {})
if base and base.get("forecast_periods"):
lines.append(f"\n--- BASE CASE MONTHLY FORECAST ---")
lines.append(
f" {'Period':>6s} {'Revenue':>12s} {'Gross Profit':>12s} "
f"{'Op. Income':>12s}"
)
lines.append(" " + "-" * 48)
for p in base["forecast_periods"]:
lines.append(
f" {p['period']:>6d} {fmt_money(p['revenue']):>12s} "
f"{fmt_money(p['gross_profit']):>12s} "
f"{fmt_money(p['operating_income']):>12s}"
)
# Cash Flow
cf = results["rolling_cash_flow"]
lines.append(f"\n--- 13-WEEK ROLLING CASH FLOW ---")
lines.append(f" Opening Balance: {fmt_money(cf['opening_balance'])}")
lines.append(f" Closing Balance: {fmt_money(cf['closing_balance'])}")
lines.append(f" Net Change: {fmt_money(cf['net_change'])}")
lines.append(
f" Minimum Balance: {fmt_money(cf['minimum_balance'])} "
f"(Week {cf['minimum_balance_week']})"
)
if cf.get("cash_runway_weeks"):
lines.append(f" Cash Runway: {cf['cash_runway_weeks']:.0f} weeks")
lines.append(f"\n Weekly Detail:")
lines.append(
f" {'Wk':>3s} {'Inflows':>10s} {'Outflows':>10s} "
f"{'Net':>10s} {'Balance':>12s}"
)
lines.append(" " + "-" * 50)
for w in cf["weekly_projections"]:
notes = f" {w['notes']}" if w["notes"] else ""
lines.append(
f" {w['week']:>3d} {fmt_money(w['total_inflows']):>10s} "
f"{fmt_money(w['total_outflows']):>10s} "
f"{fmt_money(w['net_cash_flow']):>10s} "
f"{fmt_money(w['closing_balance']):>12s}{notes}"
)
lines.append("\n" + "=" * 70)
return "\n".join(lines)
def main() -> None:
"""Main entry point."""
parser = argparse.ArgumentParser(
description="Driver-based revenue forecasting with scenario modeling"
)
parser.add_argument(
"input_file",
help="Path to JSON file with forecast data",
)
parser.add_argument(
"--format",
choices=["text", "json"],
default="text",
help="Output format (default: text)",
)
parser.add_argument(
"--scenarios",
type=str,
default="base,bull,bear",
help="Comma-separated list of scenarios (default: base,bull,bear)",
)
args = parser.parse_args()
try:
with open(args.input_file, "r") as f:
data = json.load(f)
except FileNotFoundError:
print(f"Error: File '{args.input_file}' not found.", file=sys.stderr)
sys.exit(1)
except json.JSONDecodeError as e:
print(f"Error: Invalid JSON in '{args.input_file}': {e}", file=sys.stderr)
sys.exit(1)
builder = ForecastBuilder(data)
scenarios = [s.strip() for s in args.scenarios.split(",")]
results = builder.run_full_forecast(scenarios)
if args.format == "json":
print(json.dumps(results, indent=2))
else:
print(builder.format_text(results))
if __name__ == "__main__":
main()