Unit Price Database Manager for Construction

Overview

Manage and maintain construction unit price databases. Update prices from vendors, apply location and time adjustments, track price history, and ensure estimating accuracy.

Business Case

Accurate unit prices are critical for:

• Competitive Bids: Win work with accurate pricing
• Cost Control: Avoid budget surprises
• Vendor Management: Track supplier pricing
• Historical Analysis: Understand price trends

Technical Implementation

from dataclasses import dataclass, field
from typing import List, Dict, Any, Optional
from datetime import datetime, date
from decimal import Decimal
import pandas as pd
import json

@dataclass
class UnitPrice:
    code: str
    description: str
    unit: str
    base_price: Decimal
    labor_cost: Decimal
    material_cost: Decimal
    equipment_cost: Decimal
    effective_date: date
    expiration_date: Optional[date] = None
    source: str = ""
    vendor: str = ""
    location: str = "National Average"
    notes: str = ""
    tags: List[str] = field(default_factory=list)

@dataclass
class PriceUpdate:
    code: str
    old_price: Decimal
    new_price: Decimal
    change_pct: float
    updated_at: datetime
    updated_by: str
    reason: str

@dataclass
class VendorQuote:
    vendor_name: str
    item_code: str
    quoted_price: Decimal
    quote_date: date
    valid_until: date
    quantity_break: Optional[int] = None
    notes: str = ""

class UnitPriceDatabaseManager:
    """Manage construction unit price databases."""

    # Location adjustment factors
    LOCATION_FACTORS = {
        'New York': 1.32, 'San Francisco': 1.28, 'Los Angeles': 1.15,
        'Chicago': 1.12, 'Boston': 1.18, 'Seattle': 1.08,
        'Denver': 1.02, 'National Average': 1.00,
        'Houston': 0.92, 'Dallas': 0.89, 'Phoenix': 0.93,
        'Atlanta': 0.91, 'Miami': 0.95
    }

    def __init__(self, db_path: str = None):
        self.prices: Dict[str, UnitPrice] = {}
        self.price_history: Dict[str, List[UnitPrice]] = {}
        self.vendor_quotes: Dict[str, List[VendorQuote]] = {}
        self.updates: List[PriceUpdate] = []
        self.db_path = db_path

    def add_price(self, price: UnitPrice) -> str:
        """Add or update a unit price."""
        code = price.code

        # Track history
        if code in self.prices:
            if code not in self.price_history:
                self.price_history[code] = []
            self.price_history[code].append(self.prices[code])

            # Record update
            old_price = self.prices[code].base_price
            if old_price != price.base_price:
                change_pct = float((price.base_price - old_price) / old_price * 100)
                self.updates.append(PriceUpdate(
                    code=code,
                    old_price=old_price,
                    new_price=pric...