Engineering
Technology

Lesson 16 'ඇස්තමේන්තු කරණය' (Estimating) හි ප්‍රධාන මාතෘකා:

• 📋 Estimate Types — Preliminary, Detailed, Revised estimates
• 📄 Bills of Quantities (BOQ) — preparation, format, take-off
• 📐 Material Quantity Calculation — area, volume, linear; waste allowances
• 👷 Labour Cost — skilled/unskilled; productivity rates; labour constants
• 💰 Overhead & Profit — site overhead, general overhead (10–15%), contingency (2–5%)
• 🔢 Rate Analysis — Unit Rate = Material + Labour + Plant + Overhead + Profit
• 📑 Tender Documents — Notice to tender, specifications, drawings, BOQ, conditions
• 📃 Contract Types — Lump sum, Unit rate, Cost plus, Design & Build
• 📅 Project Planning — Gantt chart, CPM Critical Path, PERT analysis
• 🏛️ Valuation & Depreciation — Straight line, Declining balance

BOQ Format:

Item No. | Description | Unit | Qty | Rate (Rs.) | Amount (Rs.)

Rate Analysis — Unit Rate build-up:

Material cost + Labour cost + Plant cost + Overhead (10–15%) + Profit (5–10%) = Unit Rate

Tender Sum:

• Subtotal + Preliminary + Overhead + Profit + VAT + Contingency (2–5%)

AL Tech Hub (altechhub.lk) හි Lesson 16 Downloads කොටසෙන් නොමිලේ:

• 📄 Full Notes PDF — 6.5 MB, 88 pages
• 📄 BOQ Preparation Guide — 2.4 MB, 24 pages
• 📄 Rate Analysis Notes — 2.2 MB, 22 pages
• 📄 Tender Documents Reference — 2.0 MB, 20 pages
• 📄 Project Planning CPM & PERT — 2.6 MB, 26 pages
• 📗 Sample BOQ Template (XLSX) — 0.9 MB, editable
• 📊 Slide Deck (PPTX) — 8.8 MB, 56 slides
• 📝 Practice Q&A (DOCX), Past Papers, 🗜️ Complete Bundle (ZIP 29 MB)

Gantt Chart — Bar chart: activities vs time:

• Visual, simple; no dependency logic for complex projects

CPM (Critical Path Method) — Network diagram:

• Fixed durations; Critical Path = longest path = min project duration
• Float/slack calculated; construction & manufacturing projects

PERT — Probabilistic durations:

te = (to + 4tm + tp) / 6  |  to=optimistic, tm=most likely, tp=pessimistic