BRC Academy · Primavera P6

EPS and OBS in Primavera P6

Lesson 3 of 60 · Beginner · 12 min read · Ben Abbasi, PMP

Before you add a single activity in Oracle Primavera P6, two structures decide where every project lives and who can touch it: the Enterprise Project Structure (EPS) and the Organizational Breakdown Structure (OBS). Get them right and a P6 database stays tidy for years. Get them wrong and you end up with contractor schedules overwritten, what-if copies rolling up into portfolio reports, and nobody sure which file is the accepted baseline.

Learning outcomes

  • Explain what the EPS and the OBS are in P6 and how they differ from a project's WBS.
  • Build an EPS with nodes, projects and more than one root node, using the Enterprise menu in P6 Professional.
  • Describe how the responsible manager field, OBS elements and project security profiles combine to control access.
  • Design an owner-side EPS and OBS that keeps contractor submissions, the accepted baseline and owner what-ifs apart.

The lesson

Three hierarchies, three jobs

New P6 users often confuse three breakdown structures because they all look like indented trees. Each one answers a different question:

  • EPS (Enterprise Project Structure) answers "where does this project sit in the organization's portfolio?" It is the filing cabinet for every project in the database.
  • OBS (Organizational Breakdown Structure) answers "who is responsible for this part of the portfolio?" It is a hierarchy of responsible managers, kept separate from the projects themselves.
  • WBS (Work Breakdown Structure) answers "what work does this project contain?" It lives inside one project. (We cover it in Lesson 6.)

The EPS and OBS are enterprise data: they belong to the whole database, not to any one project. In most organizations only a P6 administrator should change them.

The EPS: the filing cabinet

Oracle describes the EPS as the hierarchy that holds all projects in the database. You can divide it into as many levels as your portfolio needs, but projects are always the lowest level, and every project must sit under an EPS node [1]. You cannot have a "loose" project.

Two things make the EPS more than a folder tree:

  • Roll-up. P6 summarizes project data at each EPS node and up through higher levels, so a director can look at the Capital Projects node and see dates, costs and units for everything under it [1].
  • Top-down budgeting. Budgets can be set at higher nodes and distributed down to projects [1].

That roll-up is why structure matters. If a scheduler parks an experimental copy of a schedule next to the live one, the copy's dates and costs roll up too. Oracle's answer is to use more than one root node: a separate root keeps inactive or what-if projects out of the main enterprise [2]. In P6 Professional you create a second root by moving an EPS element to the top-left position with the left arrow and building the hierarchy beneath it [2].

Where to find it in P6 Professional

In P6 Professional (version 26), you build the EPS from Enterprise, Enterprise Project Structure. Click in the EPS Name column where the new element belongs, click Add, type an ID and name, pick a Responsible Manager, then use the arrow buttons to set the element's position [2]. Projects themselves are added from Enterprise, Projects, which opens the Projects window grouped by EPS. In P6 EPPM (the web version) the same work is done from Projects, EPS, and the Responsible Manager column can be added through Customize Columns if it is not shown [8].

Screenshot to come
Screenshot to come: P6 Professional v26, Enterprise > Enterprise Project Structure dialog, Northgate EPS fully expanded (NLI and WIF roots), EPS ID, EPS Name and Responsible Manager columns visible

The OBS: who is responsible

The OBS is a hierarchy of the managers responsible for your projects [5]. Two features make it different from an org chart:

  • It is global and separate from the EPS. Because the OBS is maintained on its own, you can change who is responsible during a project's life without restructuring the projects [3]. When a project manager leaves, you reassign the OBS element, not the project.
  • It describes roles, not people. An OBS element such as "NDC Owner's Scheduler" is a responsibility. Users are attached to it later, and several users can share one element [8].

In P6 Professional you open the OBS from Enterprise, OBS. Click the OBS Name column label to show the hierarchy, select the element above the position you want, and click Add. The dialog has a General tab for the name and description, a Users tab showing who is attached and with which security profile, and a Responsibility tab showing where each OBS element is assigned across the enterprise [4][5]. The Display Options bar can also show the OBS as a chart [4]. When you first build an EPS, P6 assigns a root OBS element to the root EPS node automatically [5].

The link: the Responsible Manager field

Every EPS node and every project must have an OBS element in its Responsible Manager field [2]. WBS elements inside a project carry one too. This field does two jobs at once. It records accountability (who answers for this part of the portfolio), and it drives security: users associated with that OBS element get access to the node and to every node and project in that branch [8].

That last point has a sharp edge. Oracle warns that users attached to the OBS element assigned to the root EPS node can reach every node beneath the root [8]. Be deliberate about who sits on the root.

Security: two kinds of profile

P6 Professional separates what a user can do across the enterprise from what they can do inside a project [7]:

  • Global security profile, set on the Global Access tab of Admin, Users, controls enterprise-wide actions such as editing the EPS, OBS, calendars or codes.
  • Project security profile, set on the Project Access tab, controls what the user can do in the projects they can reach. Each row on that tab pairs an OBS element with a profile [6].

To grant access, choose Admin, Users, select the user, open Project Access, click Assign, pick the OBS element, then set the Security Profile [6]. Unless a user's global profile is Admin Superuser, they cannot see project data without a project profile, and only an Admin Superuser can hand out the Project Superuser profile [6]. You define and inspect profiles under Admin, Security Profiles [6].

How a user gets access to a project in P6 Professional Four stacked boxes joined by arrows. 1, the user login, for example the owner's scheduler. 2, on Admin, Users, Project Access tab, the user is assigned an OBS element plus a project security profile, for example NDC Owner's Scheduler with NDC Editor. 3, that OBS element is the responsible manager of an EPS node, project or WBS element, for example NDC.SUB. 4, result: the user can open that branch and everything below it, with the rights the profile allows, for example edit NDC-BL00 and NDC-UP01. A side note says the global security profile, set on the Global Access tab, separately controls enterprise-wide actions. 1 User login Northgate: owner.scheduler set on Admin, Users, Project Access 2 OBS element + project security profile Northgate: NDC Owner's Scheduler + “NDC Editor” named in the Responsible Manager field 3 Responsible manager of an EPS node, project or WBS Northgate: NDC.SUB GC submissions opened with the profile's rights 4 Access to that branch and everything below it Northgate: Can edit NDC-BL00 and NDC-UP01 Separate layer: the global security profile (Global Access tab) sets enterprise-wide rights, such as editing the EPS.
Figure 3. How access works in P6 Professional: a user reaches a branch through an OBS element, and the project security profile sets what they can do there. Source: BRC, based on Oracle Primavera P6 Professional Help v26, Assign project profiles, and P6 EPPM Help, Assigning OBS Elements to the EPS [6][8].

Northgate worked example

Northgate Distribution Centre (fictional) is a 12,000 m² tilt-up warehouse in Vaughan, Ontario, built under a CCDC 2-2020 stipulated price contract by Halvorsen Builders Ltd. (fictional) for Northgate Logistics Inc. (fictional). The contractor schedules in P6 and submits native XER files; the owner keeps its master schedule in Microsoft Project. Northgate sets up its own P6 Professional database to receive, store and review those contractor files. This is the owner's database, not the contractor's.

The EPS

The owner's scheduler builds two roots. The first, NLI, is the live enterprise: Capital Projects, then Ontario, then a node for the Northgate project. Under the NDC node sit three branches that never mix:

  • NDC.BL, Accepted baseline. Holds the one baseline the owner has accepted. It is read-only for everyone except the administrator.
  • NDC.SUB, GC submissions as received. Every XER from Halvorsen is imported here untouched: the baseline as submitted, then each monthly update. These are the evidence copies.
  • NDC.REV, Owner review copies. When the owner's representative wants to test logic or run a check, they copy a submission here and work on the copy.

The second root, WIF, holds what-if copies, training files and closed projects, so none of them rolls up into the live Capital Projects totals.

Northgate owner-side EPS in Primavera P6An indented tree with two root nodes. Root 1, NLI Northgate Logistics Inc., contains Capital Projects, then Ontario, then the highlighted NDC Northgate Distribution Centre node. NDC has three child nodes: NDC.BL accepted baseline holding project NDC-BL01; NDC.SUB GC submissions holding NDC-BL00 and NDC-UP01; NDC.REV owner review copies holding NDC-UP01-R. Root 1 also holds Operations and minor capital. Root 2, WIF What-if, training and archive, holds Northgate what-if copies and Closed projects. NLI Northgate Logistics Inc. CAP Capital Projects ON Ontario NDC Northgate Distribution Centre NDC.BL Accepted baseline P NDC-BL01 Accepted baseline NDC.SUB GC submissions, as received P NDC-BL00 Baseline, as submitted P NDC-UP01 Update 1, as submitted NDC.REV Owner review copies P NDC-UP01-R Update 1, owner review OPS Operations and minor capital WIF What-if, training and archive WIF.NDC Northgate what-if copies ARC Closed projects Root node EPS node Project node P6 project
Figure 1. Northgate's owner-side EPS, with a second root for what-ifs, training and archive. Project IDs follow a fixed naming rule. Source: BRC, based on Oracle Primavera P6 Professional Help v26, Set up the EPS structure [2].

The OBS

The OBS mirrors the responsibilities, not the people. The NDC node's responsible manager is "NDC Owner's PM". Below that element sit three narrower ones, each responsible for one branch: the baseline custodian, the owner's scheduler and the owner's representative. The general contractor has no OBS element at all.

Northgate owner-side OBS in Primavera P6An indented tree of OBS elements with the EPS node each one is responsible manager for. Northgate Logistics Inc. is responsible for the NLI root. Capital Projects Director for CAP and ON. NDC Owner's PM, highlighted, for NDC. Under the PM: NDC Baseline Custodian for NDC.BL, NDC Owner's Scheduler for NDC.SUB, and NDC Owner's Representative for NDC.REV and WIF.NDC. Operations Manager for OPS. P6 Administrator for WIF and ARC. A dashed box shows the general contractor, Halvorsen Builders, with no OBS element. Northgate Logistics Inc. → NLI (root) Capital Projects Director → CAP, ON NDC Owner's PM → NDC NDC Baseline Custodian → NDC.BL NDC Owner's Scheduler → NDC.SUB NDC Owner's Representative → NDC.REV, WIF.NDC Operations Manager → OPS P6 Administrator → WIF, ARC Halvorsen Builders (GC) no OBS element Root OBS element OBS element Project lead Outside the OBS
Figure 2. Northgate's OBS, showing the EPS node each element is responsible manager for. The contractor sits outside the owner's OBS. Source: BRC, based on Oracle Primavera P6 Professional Help v26, Setting up the OBS [3].
Screenshot to come
Screenshot to come: P6 Professional v26, Enterprise > OBS dialog, Northgate OBS hierarchy expanded, Responsibility tab open for "NDC Owner's Scheduler" showing NDC.SUB

The access matrix

With profiles named "NDC Read Only" and "NDC Editor" (Northgate's own names), the administrator makes these Project Access assignments:

  • Executive sponsor: root element Northgate Logistics Inc., NDC Read Only. Sees the whole live portfolio, changes nothing.
  • Owner's PM: NDC Owner's PM, NDC Read Only. Sees all three Northgate branches.
  • Owner's representative: Baseline Custodian and Owner's Scheduler with NDC Read Only, Owner's Representative with NDC Editor.
  • Owner's scheduler: Baseline Custodian with NDC Read Only, Owner's Scheduler and Owner's Representative with NDC Editor. Imports XERs into NDC.SUB.
  • Ridgeline Architects reviewer (fictional): Owner's Scheduler with NDC Read Only. Reads submissions only.
  • Halvorsen's scheduler: no login. Submits XER files; the owner imports them.

Each user's assignments sit on separate branches, so no two rows overlap. Before go-live, the administrator logs in as a test user for each role and confirms the result matches the matrix.

Northgate access matrix: who can read or edit each EPS branch A grid with six user roles as rows and four EPS branches as columns. Executive sponsor and owner's PM: read on baseline, submissions and review copies, no access to what-ifs. Owner's representative: read baseline and submissions, edit review copies and what-ifs. Owner's scheduler: read baseline, edit submissions, review copies and what-ifs. Ridgeline reviewer: read submissions only. Halvorsen scheduler: no access to anything. NDC.BL baseline NDC.SUB submissions NDC.REV review copies WIF.NDC what-ifs Executive sponsor Read Read Read none Owner's PM Read Read Read none Owner's representative Read Read Edit Edit Owner's scheduler Read Edit Edit Edit Ridgeline reviewer none Read none none Halvorsen scheduler none none none none P6 Administrator holds the Admin Superuser global profile and is not shown. Profile names (“NDC Read Only”, “NDC Editor”) are Northgate’s own.
Figure 4. Effective access to each Northgate EPS branch by role. Source: BRC, based on Oracle Primavera P6 Professional Help v26, Assign project profiles and Setting up the OBS [3][6].
View the data
RoleNDC.BLNDC.SUBNDC.REVWIF.NDC
Executive sponsorReadReadReadNo access
Owner's PMReadReadReadNo access
Owner's representativeReadReadEditEdit
Owner's schedulerReadEditEditEdit
Ridgeline reviewerNo accessReadNo accessNo access
Halvorsen schedulerNo accessNo accessNo accessNo access
Screenshot to come
Screenshot to come: P6 Professional v26, Admin > Users, Project Access tab for the owner's scheduler test user, showing three rows: OBS element and Security Profile

Owner's move

Owners usually meet P6 through a contractor's file, so the EPS and OBS feel like someone else's problem. They are not. If you receive XER files, you need a database to put them in, and its structure is your evidence chain.

  • Demand native files. Require the baseline and every update as native XER, not just PDF, so you can import them into your own database. Put it in the schedule specification. Our schedule review guide explains what to check once you have them.
  • Keep "as received" copies untouched. Import every submission into a submissions branch that only the owner's scheduler can edit, and never work on those copies. If a delay claim arrives in month nine, you want the file exactly as the contractor sent it.
  • Lock the accepted baseline. Give the accepted baseline its own node with a custodian OBS element and read-only access for everyone else. Our post on setting and locking a baseline covers the contract side.
  • Use a second root for what-ifs. Recovery scenarios, delay tests and training copies go under a separate root so they never inflate portfolio totals.
  • Reject shared logins and shared write access. Do not let the contractor, the consultant or a generic "scheduler" account write to your database. One user, one login, one role.

Common mistakes

  1. Building the EPS around people. Nodes named after managers break the day someone leaves. Build the EPS around the portfolio (region, program, project) and put people in the OBS.
  2. Parking every user on the root OBS element. It is the quick way to make a login "work", and it gives that user every project in the database [8].
  3. Mixing submissions, review copies and what-ifs in one node. Within a year nobody can tell which "Update 4" is the contractor's. Separate branches and a naming rule (BL00, BL01, UP01, UP01-R) fix this.
  4. Treating the OBS as an org chart. The OBS is for responsibility and security. A box for every staff member just adds elements that are responsible for nothing.
  5. Changing security while users are offline. Oracle notes that changing user details, security profiles or OBS assignments while someone works offline can stop them switching back online [7]. Schedule security changes when everyone is connected.

Quick quiz

  1. In P6, every project must sit directly under:

    1. A WBS element
    2. An EPS node
    3. An OBS element
    4. A resource

  2. The Responsible Manager field on an EPS node holds:

    1. A resource from the resource dictionary
    2. A user login
    3. An OBS element
    4. A project calendar

  3. A user is assigned to the OBS element that is responsible manager of the root EPS node. What can they reach?

    1. Only the root node's own data
    2. Every node and project beneath the root
    3. Only projects they created
    4. Nothing until a WBS is assigned

  4. What decides what a user can change inside a project they can access?

    1. The project security profile on their Project Access assignment
    2. The global security profile alone
    3. The project's calendar
    4. The EPS node's ID

  5. Northgate wants delay-scenario copies kept out of portfolio roll-ups. The best structure is:

    1. A WBS element named "What-if" in the live project
    2. An activity code on the copies
    3. A separate root EPS node for what-if projects
    4. A different OBS element on the live node
Show answers and explanations
  1. B. Projects are always the lowest level of the EPS, and each one must belong to an EPS node [1].
  2. C. The responsible manager is an OBS element, which is what ties accountability and security to the node [1][2].
  3. B. Access through a responsible manager covers the node and its whole branch, so the root covers everything beneath it [8].
  4. A. The global profile controls enterprise-wide actions; the project security profile paired with the OBS element controls rights inside projects [6][7].
  5. C. Oracle suggests additional root nodes to keep inactive or what-if projects apart from the main enterprise [2].

Key terms

Enterprise Project Structure (EPS)
The hierarchy that holds every project in a P6 database and summarizes data up through its levels.
EPS node
A level in the EPS, such as a division, region or program. Projects sit under nodes.
Root node
A top-level EPS node. A database can have more than one, which keeps groups of projects apart.
Organizational Breakdown Structure (OBS)
A global hierarchy of responsible managers, kept separate from the EPS and used for accountability and security.
Responsible manager
The OBS element assigned to an EPS node, project or WBS element.
Global security profile
Controls the enterprise-wide actions a user can take.
Project security profile
Controls what a user can do in the projects reached through an OBS assignment.
Admin Superuser / Project Superuser
Built-in profiles with full rights across the application, or across a project/OBS assignment.

References

  1. Oracle. About the Enterprise Project Structure (EPS). Primavera P6 EPPM Application Administration Guide, Version 26.
  2. Oracle. Set up the EPS structure. Primavera P6 Professional Help, Version 26.
  3. Oracle. Setting up the OBS. Primavera P6 Professional Help, Version 26.
  4. Oracle. Organizational Breakdown Structure dialog box. Primavera P6 Professional Help, Version 26.
  5. Oracle. Add an OBS element. Primavera P6 Professional Help, Version 25.
  6. Oracle. Assign project profiles (P6 Professional Only). Primavera P6 Professional Help, Version 26.
  7. Oracle. Setting up user security (P6 Professional Only). Primavera P6 Professional Help, Version 25.
  8. Oracle. Assigning OBS Elements to the EPS. Primavera P6 EPPM Help, Version 24.

Verified on November 4, 2026. Menu names checked against P6 Professional Help versions 25 and 26; confirm them in your own release.

Next lesson in this trackCreate a project and project settings

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