Primavera

Oracle Primavera P6 is the industry-standard project scheduling tool for large projects. Learn EPS/WBS structure, activities and relationships (FS, SS, FF, SF with lags), calendars, constraints, scheduling (critical path, float), resources and costs, baselines, progress updating and earned value.

Metro lines, power plants and highways have tens of thousands of activities and contractual milestones. Primavera P6 schedules them, tracks progress, and reports critical paths and earned value to clients and lenders.

The planning theory (CPM, float, EVM) is the same as by hand — P6 applies it at scale.

An analogy

P6 is a giant, living CPM network: update one activity's progress and the whole project's dates, floats and forecasts recalculate.

Structure

Enterprise project structure (EPS) → projects → WBS → activities. Activities have IDs, durations, calendars and codes (area, discipline, contractor) for filtering and reporting.

Logic, calendars and constraints

Relationships (mostly FS; SS/FF with lags for overlapping work), calendars (working days, holidays, shifts), and constraints (use sparingly — they override logic and hide true float). Good schedules have every activity with a predecessor and successor (no open ends).

Resources, costs and baselines

Assign labour, equipment and costs to activities; level resources; produce cash-flow curves. Save a baseline before execution to compare planned vs actual dates and costs.

Updating, EVM and forensic analysis

Each period: set the data date, enter actual starts/finishes and remaining durations, reschedule (F9), review critical path and float erosion, and report EVM (CPI, SPI). Delay claims use time-impact analysis and windows analysis on updated schedules. Schedule quality checks (DCMA 14-point) find logic problems.

Formulas

• Finish-to-Start: Succ start ≥ Pred finish + lag
• Start-to-Start: Succ start ≥ Pred start + lag
• Finish-to-Finish: Succ finish ≥ Pred finish + lag
• Remaining duration: RD = OD × (1 − physical % complete) (approx.)

Worked example: Schedule the plinth fragment

Given: Durations and logic in the import table (working days)

Find: Milestone date (day number).

• A1000: 0–10; A1010: 10–25
• A1020 (SS + 5): starts day 15, finishes day 27 — it overlaps the excavation
• A1030: 27–35; A1040: FS 3 → 38–44
• M1000 at day 44

Answer: Plinth complete at working day 44

Worked example: Effect of overlap

Given: If A1020 were FS instead of SS 5

Find: New milestone day.

• A1020: 25–37; A1030: 37–45; A1040: 48–54
• Milestone day 54 → overlap saves 10 working days

Answer: Day 54 (10 days later)

Activity import table (Excel/CSV → P6)

Activity ID,Activity Name,WBS,Original Duration,Predecessors,Calendar
A1000,Site mobilisation,PRJ.PRE,10,,6-day
A1010,Excavation Block A,PRJ.CIV.A,15,A1000 FS,6-day
A1020,PCC & footings Block A,PRJ.CIV.A,12,A1010 SS 5,6-day
A1030,Columns to plinth Block A,PRJ.CIV.A,8,A1020 FS,6-day
A1040,Backfill Block A,PRJ.CIV.A,6,A1030 FS 3,6-day
M1000,Plinth complete (milestone),PRJ.MS,0,A1040 FS,6-day

SS 5 lets footings start 5 days after excavation starts (overlapping); FS 3 adds a 3-day curing lag before backfill.

Common mistakes

• Wrong: Using hard constraints instead of logic. — Right: Drive dates with relationships; constraints hide float and critical paths.
• Wrong: Open-ended activities (no successor). — Right: Every activity needs predecessors and successors for reliable float.

Applications

• Mega-projects: Metros, airports, refineries and power plants.
• Contract compliance: Baseline and monthly update submissions to clients.
• Claims & disputes: Delay analysis and extension-of-time claims.

Key takeaways

• EPS → WBS → activities with sound logic.
• FS/SS/FF + lags model real overlaps.
• Baseline, update, reschedule, report EVM.
• Avoid constraints and open ends.

Going further

• DCMA 14-point assessment: Checks logic, leads/lags, constraints, float and resources.
• Risk analysis: Primavera Risk Analysis runs Monte Carlo on schedules.
• Integration: Links to ERP/cost systems and BIM (4D) for control.