Setting Up a P6 Project
Last reviewed 9 September 20262,041 words9 min read
The settings to get right before you type an activity — because most of them can't be fixed cleanly afterwards
🟩 In one line: Fifteen minutes in Admin Preferences, Project Details and Scheduling Options before the first activity saves weeks of unexplained date movement later — this page is the checklist, in the order you click.
👤 Who this is for: J/M. Prerequisites: none; links out to the pages that argue each setting.
First, let's be honest about why this page exists
Most planners inherit a database, copy an old project and start typing. The old project carried someone else's percent-complete type, someone else's critical-path definition and a calendar with 8 hours a day on a site working 10. Nobody notices until the first update, when every duration shows as 1.25 times what was typed and the critical path highlights half the network.
Every setting below is argued properly on its own page. This page is just the order to set them and the value to choose.
🟨 The standard — what "good" looks like
| Source | What it asks for (paraphrased) | Setting it touches |
|---|---|---|
| AACE RP 38R-06 | Schedule basis records calendars, settings, methods | Everything below goes in SBM section on tool settings, with a screenshot |
| DCMA 14-Point, Metrics 1–5, 12 | Logic, leads, lags, relationship types, hard constraints, critical path test | Defaults for new activities; scheduling options |
| GAO Schedule Assessment Guide, BP 1 and 6 | Capture all activities; confirm the critical path | WBS, activity ID scheme, Longest Path |
| PMI Practice Standard for Scheduling, 2nd ed. | Schedule model settings documented and consistent | Same |
| Client schedule specifications (typical Gulf) | Often mandate: hours per day, Longest Path, physical % complete, activity ID format, coding | Check the spec before this page — it overrides it |
🟢 Rule: set Admin Preferences first, then Project Details, then Scheduling Options, then calendars, codes and UDFs — and screenshot the lot into the SBM before the first activity exists.
How it actually works
1. Admin Preferences (Admin → Admin Preferences) — database-wide, do once, agree with the database owner
| Tab | Setting | Value | Why |
|---|---|---|---|
| Time Periods | "Use assigned calendar to specify the number of work hours for each time period" | Ticked | Durations display in days per each calendar's real hours (hours-per-day-and-duration-display) |
| Earned Value | Technique for computing performance % complete | Activity % complete | Physical % drives EV; changed per WBS where a rule of credit applies |
| Earned Value | Technique for computing ETC | PF = 1 (or as SBM states) | Recorded in SBM; argued in earned-value-basics |
| ID Lengths | Activity ID, WBS code, resource ID | ≥ 20 / 20 / 20 | Zone-coded IDs run long |
| Data Limits | Activity codes, baselines per project | Raise if needed | Three baselines per project minimum |
2. Project Details (Enterprise → Projects, select project, Details at bottom)
| Tab | Setting | Value | Why |
|---|---|---|---|
| General | Project ID, name, Responsible Manager (OBS) | Per contract numbering | ID appears on every export |
| General | Status | Active | Planned/What-If projects don't summarise |
| Dates | Planned Start | Contract commencement | Never later than the first activity |
| Dates | Must Finish By | Blank | It is a hidden Finish On or Before on the whole project; use a constrained milestone instead |
| Dates | Data Date | = Planned Start at set-up | Moves only in the monthly update |
| Defaults | Duration Type | Fixed Duration & Units | Durations don't move when resources change (p6-duration-types-explained) |
| Defaults | Percent Complete Type | Physical | Never Duration on production work |
| Defaults | Activity Type | Task Dependent | Others chosen deliberately, per activity |
| Defaults | Calendar | 6-day site calendar (project-level) | The most common calendar becomes the default |
| Defaults | Auto-numbering | Prefix per WBS scheme; increment 10 | Room to insert |
| Settings | Character for WBS separator | "." | Client spec may dictate |
| Settings | Baseline for earned value calculations | Project baseline | Points EV at the accepted baseline, not a user's |
| Settings | Define critical activities | Longest Path | Float ≤ 0 breaks across calendars (critical-path-vs-longest-path) |
| Calculations | Activity % complete based on activity steps | Ticked where steps are used | Rules of credit via steps |
| Calculations | Link Budget and At Completion for not started activities | Ticked | Stops budgets drifting before start |
| Calculations | When updating actual units or cost | Subtract actual from At Completion | Keeps At Completion honest; SBM records choice |
| Calculations | Recalculate actual units when duration % changes | Unticked | Actuals come from records, never from % |
| Calculations | Link actual and actual this period | Ticked | Period reporting works |
3. Scheduling Options (Tools → Schedule → Options, F9)
Set once, screenshot into the SBM, check on every received file. Full table on scheduling-options; the short version:
| Setting | Value |
|---|---|
| When scheduling progressed activities | Retained Logic |
| Calculate SS lag from | Actual Start |
| Define critical activities as | Longest Path |
| Compute total float as | Finish Float |
| Calendar for scheduling relationship lag | Predecessor Activity Calendar |
| Make open-ended activities critical | Unticked (tick only to hunt dangles) |
| Schedule automatically / Level during schedule | Both unticked |
| Log to file | Ticked, every run |
| Advanced: multiple float paths | Free Float; 5–10 paths; end at contractual completion milestone |
4. Calendars (Enterprise → Calendars)
Create project calendars, not global, unless the database owner has enterprise standards. Global calendars travel in every XER and pollute other databases.
| Calendar | Hours/day | Days | Exceptions |
|---|---|---|---|
| Site 6-day | 10 (8.5 mid-Jun to mid-Sep for external work) | Sat–Thu | Eid, National Day, Ramadan reduced hours as date exceptions |
| Curing 7-day | 24 | All | None |
| Office 5-day | 8 | Sun–Thu (or Mon–Fri per client) | Public holidays |
| Consultant review | 7-day, 24 h | All | None — only where the contract counts calendar days |
Set each calendar's own Time Periods button to its real hours. Details on calendar-setup-and-holidays.
5. Structures and codes
| Item | Set-up | Note |
|---|---|---|
| WBS | Contract → phase → area/level → discipline; ≤ 6 levels | wbs-structure-design |
| Activity codes (project-level) | Area, Level, Discipline, Subcontractor, Change Ref, Split From | Project codes export cleanly; global codes don't |
| UDFs | Duration Basis (text), Qty, Unit, Rate, Crew (numbers) | crew-and-manhour-formulas |
| Notebook topics | Logic Basis, Forecast Basis, Change Basis, Recovery Basis | Created once in Admin Categories |
| Activity ID scheme | AREA-LVL-DISC-NNN, e.g. T1-L05-BLK-020 | Readable without opening the activity |
| Milestones | Contract commencement; every contractual key date; planned completion; contractual completion (constrained FOoB) | milestones-and-key-dates |
6. User Preferences (Edit → User Preferences) — per user, per machine, not per project
| Tab | Setting | Value |
|---|---|---|
| Time Units | Durations shown in | Days, 0 decimals (hours when checking lags) |
| Time Units | Units/Time | Units/day |
| Dates | Format | DD-MMM-YY, no time, or time shown when diagnosing |
| Calculations | Resource assignments: preserve units, duration and units/time | Per SBM |
These do not travel with the XER. Every reviewer opening your file with 8-hour display will see different durations — the SBM screenshot is your defence.
🟥 Where people go wrong
- Copying last year's project as the template. Someone else's percent type, constraints and global codes come with it. Build from a clean project, or strip the copy to zero activities and audit every tab first.
- Must Finish By set to the contract date. It constrains everything and hides real negative float behind a project-level constraint nobody sees in the activity table. Blank; constrained milestone instead.
- Default percent type left on Duration. Every production activity then earns progress by the calendar. Physical, before the first activity exists.
- Global calendars and global codes for a single project. They arrive in every XER the client, the consultant and the next subcontractor imports. Project-level for everything project-specific.
- Admin Preferences hours-per-day not set to "use assigned calendar". A 10-hour site day displays a typed 10 days as 12.5. The correction is one tick — and it is the first thing checked on a received file.
- No screenshot in the SBM. Six months later nobody can prove what the settings were at baseline, and the client's reviewer has changed three of them in their own copy.
⚖️ When you're challenged
"Why can't I just start typing? The settings can be changed later." Some can. Percent type can't be changed cleanly once actuals exist, hours-per-day changes redisplay every duration, and the critical-path definition changes what's red in every report you've already issued. Fifteen minutes now.
"The client's spec says Total Float ≤ 0 for critical. You've set Longest Path." Both are set — the report filter uses the spec's float definition, the scheduling option uses Longest Path so the path is continuous across the curing and consultant calendars. The SBM records both and the narrative reports both where they differ.
"Your durations look different on my machine." Your User Preferences show 8-hour days; the site calendar is 10. The SBM screenshot shows the setting; tick "use assigned calendar" in Admin Preferences and they'll match.
📄 Related pages
- Scheduling options — the F9 dialog in full
- Hours per day and duration display — the Admin Preferences tick
- Calendar Setup and Holidays — the four calendars
- P6 Activity Types Explained — why Task Dependent is the default
- P6 Duration Types Explained — why Fixed Duration & Units
- Percent Complete Types — why Physical
- WBS Structure Design — the structure under the codes
- Schedule Basis Memorandum — where the screenshots go
✏️ Worked example
Set-up sheet for a 14-storey residential tower in Abu Dhabi, pasted into SBM section 3 before activity 1:
| Item | Value |
|---|---|
| Project ID / name | AUH-RT14 / Residential Tower, Plot 14 |
| Planned start / data date | 15 Jan; 15 Jan |
| Must Finish By | Blank |
| Defaults | Task Dependent; Fixed Duration & Units; Physical %; calendar "AUH-RT14 Site 6d 10h" |
| Critical | Longest Path (report filter also shows TF ≤ 0) |
| Scheduling options | As table above; screenshot attached |
| Calendars (project) | Site 6d 10h (summer 8.5h 15 Jun–15 Sep); Curing 7d 24h; Office 5d 8h; Review 7d 24h |
| Activity codes | Area (T1, POD, EXT); Level (B2–L14, RF); Discipline (STR, BLK, MEP, FIN, FAC); Subcontractor; Change Ref; Split From |
| UDFs | Duration Basis; Qty; Unit; Rate; Crew |
| Notebook topics | Logic Basis; Forecast Basis; Change Basis; Recovery Basis |
| ID scheme | AREA-LVL-DISC-NNN, increment 10 |
| Milestones | Commencement; Structure topping-out KD; Building envelope KD; Planned completion; Contractual completion (FOoB 30 Apr) |
| Admin Preferences | Use assigned calendar: ticked; EV = Activity %; ETC PF = 1 |
Time taken: 40 minutes including calendar exceptions. Time it would have cost to fix at Update 3: two days and a re-issued narrative.
📖 References
- AACE International RP 38R-06, Documenting the Schedule Basis
- DCMA 14-Point Schedule Assessment, Metrics 1–5, 12
- GAO Schedule Assessment Guide (GAO-16-89G), Best Practices 1, 6
- PMI Practice Standard for Scheduling, 2nd ed.
- Oracle Primavera P6 Professional User Guide — Admin Preferences; Project Details (General, Dates, Defaults, Settings, Calculations); Schedule Options; Calendars; Activity Codes; User Defined Fields; User Preferences (field labels as in P6 Professional v20; earlier versions differ)
From the field
Experience from working planners. Unreviewed — read it as experience, not guidance.
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