Doing the weebis and the obis

new dances for project managers?

Concerns of Project Managers

PM Software Forum

Harvey A. Levine
Feature Editor


Harvey A. Levine, principal, The Project Knowledge Group (21 Pine Ridge, Saratoga Springs, NY 12866) has been a practitioner of project management for over thirty years, primarily with General Electric Company, and is a past chairman of PMI. Mr. Levine has been adjunct professor of project management at Rensselaer Polytechnic Institute, Troy, NY, and is the author of the book Project Management Using Microcomputers as well as several articles.

Every discipline has its alphabet soup… abbreviations or acronyms for seemingly non-mistakable terms and functions. In project management, we have the WBS, OBS, and RBS, which, of course, everyone clearly understands. Right? It should only be that simple.

The truth is that these terms, as being applied via popular project management software packages, are being bastardized. New terms are being introduced to replace the basic three, and even worse, these basic terms are being applied to functions that differ from the traditional concepts.

In this latter situation, is it unproductive, unfair and unethical to misuse a common term for something other than its common understanding? In some cases, this deviation may primarily be a careless application of the wrong term or willingness to stray from the traditional concept. In other, more deleterious cases, the misuse of the terms will make it appear that the product has capabilities that are not present. For instance, the availability of a data field that contains an activity tag number called “WBS,” does not mean that the product has a true WBS capability. Any full function WBS (or OBS or RBS) must be able to facilitate data summarization and reporting by these codes, to any level. Using WBS codes for sorting and selecting (filters) does not constitute a WBS function. To ferret out the perpetrators of these dastardly crimes, we have summoned the PM Software Forum Weebis Patrol.


Fearing that many of us need something more simple and visual (than WBS, etc.), several project management software developers, especially at the lowend, focus on an Outline mode. This provides a practical and very readable method of defining and displaying a hierarchical relationship of individual tasks within a larger project (and everyone knows what an outline is). It works, but with limitations. The biggest constraint is that the outline provides only one project hierarchy, when there may be several. For instance, the project manager may wish to view the project using a work breakdown based on the phases of the project, or geographical divisions, or perhaps deliverables. A functional manager is often more interested in an outline that reflects the organizational structure, such as division, department, section, discipline, etc. The corporate comptroller may wish to segment and interrogate the data based on a code of accounts. So, you can see that a single outline may not do the job for everyone.

Not to worry! Many of the mid- and high-end project management packages (and one low-end; Project Scheduler 5) provide multiple code fields for this multiple outline function. Lately, however, some confusion may be creeping into the scene. In an attempt to expand upon the hierarchical capabilities of the software, and to create some standard terminology, the market has produced a set of new terms and formats. However, these are anything but standard.


In order to facilitate frameworks for project plans (a very useful function), we have invented the WBS (Work Breakdown Structure), the OBS (Organization Breakdown Structure), and the RBS (Resource Breakdown Structure). One of my clients referred to them as the Weebis, Obis, and Reebis (which, once you stop laughing, is easier to say). But! These terms do not always mean the same thing.


Ordinarily, we would expect the outliner function to provide a summarization capability. That is, we expect the project data to be able to be rolled-up to the various outline levels. This is almost universally true, for all outliners. We would expect similar capabilities from a WBS. But, look out! Occasionally, you will come across a WBS function wherein the WBS numbers are used solely as IDs, rather than summarization points. In this case, the term WBS is really misapplied, as the field is nothing more than an auxiliary code field. You will run into this situation primarily in the low-end product group, where the outline-based products are trying to appear to have WBS functionality.

The other thing to lookout for is varied use of the term OBS (see below). It can mean two very different things. In fact, I have found the terms to be used quite differently in two products being distributed by the same project management software vendor.

To set the stage for a clarification of these terms, and their use, it is important to establish a clear understanding of a basic premise of project data. There are two basic areas that are defied and managed. One is the work itself, consisting of the project(s) and the tasks that are to be accomplished within the project. The other is the organization, and the resources that are going to accomplish the work. It is very important to recognize this distinction. All project management software is based on this protocol. There is task information, and there is resource information. We need to make the distinction between frameworks for the work (tasks) and frameworks for the resource data.


The Outline, for those programs using this mode as the primary (or only) framework, is always a work (task) framework.

The WBS is fairly clear cut. It is essentially the same thing as the Outline. It is the primary hierarchy for the tasks within a project. It applies to the work, as opposed to the resources.

The RBS (in the few places that it is actually used) applies to the resources. It provides a basis for defining a parent group for each resource (perhaps all resources within a specific discipline). For instance, we might have Tom, Joan, and Iris, who are mechanical designers. The parent category would be Mech Eng'ng & Design, which, in turn, is a part of the Eng'ng & Design Function.

The problem child in this alphabet soup is the OBS. Sometimes it is set up to be the exact same function as the RBS. In other words, it is an RBS that is called OBS. Other times it is set up to be a second variation of the WBS (as we noted, it is quite normal for there to be several WBS-type hierarchies). There is certainly a significant difference in these two concepts, as the former (RBS) is used only for the resource data, whereas the latter is used solely for task data.

Lastly, about these definitions, I will again state that a true WBS, OBS, or RBS must be able to facilitate data summarization and reporting by these codes, to any level. Using WBS codes for sorting and selecting does not constitute a WBS function. Having a data field to designate a group for resources (even if called RBS or Resource Outline), is not an RBS if it does not allow you to look at resource assignment data, at any level of the coding structure.


We can appreciate that it is difficult for our readers to sift through the product descriptions and claims, especially as they might apply to these outliner/framework functions. So, the PM Software Forum has done this for you. Space limits prevent us from discussing every product, so we have included the more popular programs. We try our best to be accurate, and to stay up-to-date. But even this reviewer is capable of misinterpreting a product feature, and we apologize in advance to our readers and product vendors. If there are any misconceptions, please let us know. Our summary review is arranged by price group, a service of the PM Software Forum Weebis Patrol.


The following is offered as an attempt to clarify the concepts of WBS, OBS, and RBS. PMNETwork welcomes discussion of the following to aid in achieving agreement between vendors and reducing confusion to users. Please send your comments to PMI Communications Office, P.O. Box 189, Webster, NC, 28788, ATTN: PM Software Forum.

Common Characteristics

WBS, OBS, and RBS:

  • Provide a logical breakdown of a project into successive levels showing increasing detail.
  • Are composed of elements related in such a manner that each element is associated with one and only one higher level element.
  • The elements can be progressively summarized upward to present the time spans, or resource and cost total for the next higher level element, and ultimately for the project.

Differentiating Characteristics

At the lowest levels of detail, in the project database, the codes are associated:

  • With activity records for the WBS
  • With activity records for the OBS
  • With resource assignment records for the RBS

The Logic of the Breakdown Structure

  • WBS is generally based on deliver ables, sometimes within phases of a project.
  • OBS is generally based on organizational entities.
  • RBS is generally based on common resource usage wherever used in the project, i.e., all electricians; on common types of work whereverappearing in the project, i.e., all concrete placement; or to differentiate between work to be expensed versus capitalized. In many programs, the term Cost Account is substituted for RBS. If the Cost Account function provides a means of defining a code structure, at the assignment level, it is the functional equivalent of an RBS.

Usage Characteristics

  • WBS — to accumulate all timing, resource data, and costs associated with a project as incurred in performing each activity in the project. It is important for scope management as well as analyzing earned value.
  • OBS — to accumulate all timing, resource data, and costs in a project for which an organizational entity is responsible and relate them to the administrative budgeting process of the organization.
  • RBS — to aggregate all timing, resource data and costs in a manner required for control by trade, skill or profession or by expense versus capitalization accounts.

Low-end (under $1000)

Among the lower-end products, Microsoft's Project for Windows; Computer Associates’ SuperProject; Symantec's TimeLine 5.0, TimeLine for Windows and On Target; Claris’ MacProject PRO; and MicroPlanning's InstaPlan are classic Outliners. In these products, the outline is used as the WBS. But (and this has been a continuing theme in this column), there are considerable differences in how these products actually approach the WBS (and OBS) features.

Microsoft Project for Windows, TimeLine for Windows and On Target have a column for the WBS, which is associated with the outline. Summarization is only via the outline. The WBS is essentially an ID field, which can be used for sorting and filtering. TimeLine 5.0 (DOS) appears to have greater functionality in this area. It boasts a WBS manager and an OBS field. But even here, it is the outliner that handles summarization, and the WBS and OBS fields are limited to sorting and filtering. The OBS field is associated with tasks (as opposed to assignments), and therefore acts solely as a second task code field.

InstaPlan has WBS codes and OBS codes. The WBS codes are directly linked to the activity outline view, which provides the traditional rollup capabilities. The OBS is linked to the resource outline view. This provides the means of defining a hierarchy for the resources. This view, however, only shows the resource definition data. You cannot get a list or summary of task and assignment information in the Resource Outline.

So here we have five products that have a WBS field (two that have OBS fields, as well), none of which provide full-function WBS or OBS summarization and reporting capabilities. It's the old “can't judge a book by its cover” theme, again. However, putting the possible misconceptions about WBS capabilities aside, these products do provide some WBS-type summarization functions, via the outline.

SuperProject 3.0 (DOS and Windows) has a WBS coding function and an account coding function. The latter is essentially an RBS. The account codes are associated with each resource assignment. There is an account outline view, which organizes the task and assignment data by account codes. The WBS codes are associated with the task outline. In each view, data can be displayed by assignment, task, heading, or a combination of these. This provides some summarization control, for both the task (WBS) and resource (accounts) data.

In this low-end group, only Scitor's Project Scheduler 5 provides true WBS/OBS/RBS capabilities. PS5 has two task hierarchies (WBS and OBS) plus a resource hierarchy (RBS). Each of the ten-character task codes or the five-character resource code can be summarized using any position of the coding structure. Wildcard entries can be used, and the codes can also be used for sorting and filtering. While the concept of using these codes for summarization, sorting and filtering is certainly not unique to PS5, it is the only product in this group to provide full rollup capability by WBS, OBS, and RBS.

SureTrak, from Primavera Systems, has a WBS function. Users must define summary activities and assign WBS numbers. Certain predefine reports can be summarized by WBS. Three additional user code fields are available for limited summarization and grouping. There is no resource hierarchy capability.

MacProject PRO, Claris’ new Macintosh-based scheduler, has a strong outline mode, with an extra feature. Users may create an outline for a project, including items that do not have to be included in the actual task-based plan. This allows the user to brainstorm through the project, defining tasks and schedules for selected portions of the outline. MacProjectPRO automatically generates WBS numbers from the outline, which is used for summarization.

Mid-range ($1OOO-$25OO)

WST'S Texim Project for Windows and ABT's Project Workbench for Windows (two new products) are innovative products that are not afraid to move outside of traditional pricing and attribute classes. This definition extends to the Outline/WBS area. Both products are designed around a hierarchical concept, but quite differently.

Project Workbench (in the DOS version) was one of the earlier programs to be based on the outliner approach. This approach is continued and enhanced in the Windows version. The outline function, in PWW, is limited to four levels. By default, they are: Project, Phase, Activity, and Task/Milestone. Users may select their own terms for each level. PWW refers to this hierarchy as the WBS, but there is no WBS field (there are four utility text fields that could be used to hold a WBS code, but the outline is the method for summarization and reporting). Although limited to this outline mode, the creative and powerful viewing/reporting capability of the new Project Workbench allows for extensive summarization functionality.

Texim Project provides two basic structures for viewing and accessing all project data. These are called WBS and OBS. The OBS, however, is what I described earlier as an RBS. That is, it is a hierarchical structure for the resouces and assignment data. Most views are associated either with the WBS (activities) or OBS (resources). There is a strong visual approach (WBS and OBS diagrams) and the user will usually point and click on a specific node in the diagram to get to details for that portion of the project. WBS and OBS numbering are established automatically as the items are added to the diagrams. They can be overridden. There are also 20 user-defined data fields available for additional coding.

Schedule Publisher, distributed by Lucas Management Systems, has a very strong graphical approach, but is extremely weak in the outline/WBS department. There is no traditional outline mode, nor any kind of WBS. There is a limited “rollup” function that places summary bars on the Gantt chart for logical groups of tasks. Some summary data is available on certain table views. Setup and control is difficult.

High-end ($2500-$6000)

All of the products at the high end have traditionally exhibited advanced WBS-type characteristics. Many of these are limited to task-oriented hierarchies, but some also offer resource structures.

Computer Aided Management introduced a graphical WBS approach with ViewPoint, several years ago. CAM’s latest offering, PARISS Enterprise, continues and improves upon that approach. Enterprise provides only one WBS, called the Project Tree. It is quite similar to Texim Project's WBS in that it depicts the project (or multiple projects) in a graphical “tree” diagram. The user can use this diagram to patch together sections of the larger work. Although additional structures are not provided, per se, Enterprise provides three user code fields that can be used for summarization. These are all task-oriented code fields. The summary codes can be used to place additional “summary” nodes on the graphic time-phased primary view. Enterprise also provides a budget code capability, but this is limited to sorting and filtering usage.

WST's Open Plan comes with two predefine code fields; WBS and OBS. Both of these apply to activities. This is different from WST’s Texim Project, where the OBS applies to resources. Users may define additional code fields. The screen forms must be modified to display the additional activity code fields. A “screen generator” function is provided. Reporting functions can utilize these code fields for summarization. This dual (WBS/OBS) activity coding approach supports the traditional C/SCSC performance measurement and reporting concepts, whereas the juncture of a WBS code and an OBS code represents a cost account. A resource breakdown structure capability is not available.

Primavera Systems’ two high-end schedulers; Primavera (P3) and Finest Hour (FH), have up to 24 fields which can be defined and setup by the user for structured summarization and reporting. It is also possible to define titles and summarize data based on a combination of data fields. These are all activity code fields. P3 and FH also use cost account codes, which can be associated with resource assignments. The cost account codes are used to segregate and summarize resource and cost data at the assignment level. The latest version of P3 and FH added hierarchical resource codes (a single grouping level above the individual resource). In addition to supporting certain advanced resource leveling features, the hierarchical resource codes can be used for summarizing resource data on resource and cost reports. P3 and FH also provide a capability for custom data items, eight each for activities and for resources/cost accounts (assignment level). These are not used for summarization.

Upper High-end (over $6000)

New project management software products are emerging for the PC platform, under the general heading of “client-server” solutions. Two of these have recently been introduced by two of the older multi-platform project management software providers. Lucas Management Systems upgraded the older version of Prestige for use on PC and VAX platforms, using a SQL database and (on the PC) a Windows front-end. PSDI has combined the functionality of PROJECT/2 with the graphic feel of QWIKNET Professional in a totally new product called PROJECT/2 Series/X (P/X, for short). The PC version uses a Windows interface. A VAX version is also available.

Artemis Prestige offers strong WBS capabilities. It uses up to eight user-defined fields per project (out of an unlimited library of code sets) for activities and two code sets for resources. It also has eight code sets for projects, to support multiproject rollups. For each of these eight-character fields, you may define a format (A, N, or A/N), create a lookup table, and define a breakdown structure. There can be up to 99 levels defined in each breakdown structure.

PSDI's PROJECT/2 Series/X provides multiple framework options, offering an outline mode and multiple work breakdown structures. Breakdown structures can be created for both activities and resources. There can be up to 20 levels in a breakdown structure. A resource code field is used for the RBS. There are eight activity code fields available for use as a WBS. Breakdown structures can also be defined based on the project name field, or the activity name (for WBS) or resource name (for RBS) fields.


APRIL 1993