Contractor Estimation and Bidding Process

A structured approach to estimating costs and preparing competitive bids for government tenders. This workflow follows industry best practices used by contractors and quantity surveyors.

Overview: The Estimation and Bidding Flow

The process from a contractor’s perspective typically follows:

1. Get involved in pre-qualification
2. Study tender documents, drawings, and prepare tender summary
3. Take key decisions (bid/no-bid, JV, subcontracting, method)
4. Arrange site visit and investigation
5. Consultation, queries, and pre-bid meetings
6. Prepare construction schedule and cash flow
7. Collect information (material, labour, plant)
8. Analyse rates
9. Determine bid price and fix markup

Step 1: Pre-Qualification

Participate in the pre-qualification process. Ensure you meet eligibility criteria—registration, turnover, experience, and technical capacity. Missing pre-qualification means your bid will not be considered.

Step 2: Prepare Tender at a Glance

After studying the tender document and drawings, prepare a tender-at-a-glance summary. Focus on points with financial implications:

#	Item	What to capture
1	Client, consultant, architect	Reputation, payment history
2	Commercial terms	Contract type, penalties, incentives
3	Advances	Mobilization, plant, material advance and recovery
4	Taxes and duties	GST, local taxes, exemptions
5	Payment terms	Stage payments, retention, timelines
6	Escalation, LD, bonus	Formula, caps, bonus clauses
7	Arbitration and dispute resolution	Jurisdiction, process
8	Insurance	Requirements and costs
9	Site facilities	Power, water, storage, access
10	Client-supplied materials	Scope, rates, delivery

See our Tender-at-a-Glance Checklist for a printable checklist.

Step 3: Key Decisions

Before investing further, decide:

1. To bid or not to bid—Evaluate fit, capacity, and win probability.
2. Bid alone or in JV—Joint venture with other contractors for large or complex projects.
3. What to subcontract—Identify items and extent of subcontracted work; obtain sub-bids.
4. Construction method—Choose the most economical execution approach.

Step 4 & 5: Site Visit and Investigation

Site visit (preliminary)

• Site description and topography
• Existing services and ground conditions
• Access (road, rail, air, water)
• Labour availability in the vicinity
• Water and power availability
• Waste and earth disposal options
• Demolition or temporary works near adjoining structures
• Security and law-and-order assessment

Site investigation (detailed)

Collect:

• General site information
• Taxes, duties, and tariffs
• Applicable laws and regulations
• Meteorological data
• Access routes
• Public utilities and services
• Material availability and rates
• Labour availability and rates
• Subcontractor availability and rates
• Plant and machinery availability and hire rates

Step 6: Prepare Schedules

• Construction schedule—Split quantities on a bar chart; plan milestones
• Cash flow—Inflow (contract payments) and outflow (labour, vendors, suppliers) based on contract terms
• Labour schedule—Skilled and unskilled requirements
• Plant schedule—Equipment needed and duration
• Subcontractor schedule—Scope, rates, and timelines

Step 7: Collect Information

• Material—Requirements per unit, proportions, bulkage, wastage, breakage
• Labour—Output per hour for skilled and unskilled
• Plant and equipment—Output of different types and sizes
• Construction method—Most economical way to execute

Step 8: Rate Analysis

Three common approaches:

• Operational estimating—Activity-based
• Unit rate estimating—Per unit of measurement
• Combined—Mix of both

Choose based on tender format and your data.

Step 9: Bid Price and Markup

Bid price = Direct cost (DC) + Indirect cost (IC) + Markup

Markup covers profit, contingency, risk, and overheads. It can be expressed as:

• On cost: Bid = Total cost × (1 + Markup%)
• Off-top: Bid = Total cost ÷ (1 − Markup%)

Use our Bid Price Calculator with both options.

Bidding Models (Win Probability)

Research uses models to link markup level with probability of winning:

• Gates’ model—Probability of beating known or unknown competitors
• Friedman’s model—Uses historical bid-to-cost (B/C) ratios to estimate win probability at different markup levels
• Cash flow–based models—Markup defined using discounted cash flows

In practice, contractors often use Friedman’s approach: analyse past bids vs costs, fit a distribution, and find the markup that maximises expected value (probability × markup amount).

Indian Practices—Summary

• 82% of contractors use first-principle estimation; 18% use schedule of rates
• 55% use statistical tools for cost and win-probability
• Markup typically 1–20%; distribution varies (43% even, 5% front-load, 33% uneven)
• 68% apply correction factors for uncertainty; 18% adjust markup

Next Steps

• How to Calculate Markup—factors and formulae
• Tender Winning Strategy—process and checklists
• Bid Price Calculator—compute bid price with GST and TDS