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On CBS vs WBS

Ernesto PuyanaMember for 25 years 9 months
Created
11
2
0
Ive taught scheduling at both the bachelor and gradute level and have found the WBS concept and identification, the hardest subject for engineers and architects to grasp. In our country, most contracts are unit cost, not lump sum. And both agencies and contractors tend to visualise projects in a one-dimensional mode: cost. Therefore, the only structure they understand is CBS. Besides, the CBS in a unit cost contract tends to group similar tasks under a single tag, regardless of space and time. Any square meter of brick layed goes to the same bag, no matter where or when it is layed. WBS involves cost, space and time and demands a wider view. In my opinion, understanding the difference marks the line that separates project managers from contractors.

11 replies

Oldest first
  1. 0
    James Williams ·
    Ernesto,

    Good point, I wholly agree.

    Slighty relevant to your post - We have huge problems getting prople to think about how a WBS is useful to them, apart from the issues related to how to strucutre the thing.

    I think a large part of the problem is in getting the other project members (especially in a large organisation) to understand AND appreciate what proactive planning is all about. Until people are appreciative of the benefits that we can provide, putting some structure to the programme is of little added value.

    Perhaps I have a jaded view ?

    Jimbo
  2. 0
    Ali Hamouda ·
    Can u pls post for us one of your lecture's regarding WBS? Regards Ali ----------------
  3. 0
    Robin Jongen ·
    Maby it is wise to read the following book about WBS strucutures. Effective Work Breakdown Structures ISBN: 1-56726-135-3 Pages: 104 Date Published: 2002 Author: Gregory T. Haugan, PMP Publisher: Management Concepts Format: paperback Subject: Project Management
  4. 0
    Mehdi Rashidi Alangeh ·
    Dear all,
    For more information about WBS and CBS please see Military standard such as mil-std-884 ( or 5)

    Regrads
  5. 0
    Morteza Jafari ·
    the fast way is to going in P3 and search abour CBS and WBS, there is a brief report in this matter, it may be useful.
  6. 0
    Mehdi Rashidi Alangeh ·
    I think WBS is a main structre for coordinate with all of the lements in PM But CBS used in cost accounting & cost control section.
    I the fact WBS covers CBS ( OBS , etc) and WBS coordinate this items.

    Regards
  7. 0
    Edgar Ariete ·
    Ernesto Puyana,

    I appreciate your opinion, & I would be very grateful if you could recommend further on which planning softwares you can apply best your method of taking CBS or WBS into actual consideration.

    Thanks & regards,

    Edgar
  8. 0
    Vladimir Liberzon ·
    We usually use several WBS in one project, one of them is what is usually called CBS.
    But it is not enough. There are also cost components that may belong to one project object. Cost components are not modeled by CBS. There is a need of both - CBS and cost components.
  9. 0
    Joanne Foster ·
    In defence (Australia) we only use the WBS and there should be only 1 WBS for the project. Our standard is DEF(AUST)5664 (you can download a copy of this from http://www.defence.gov.au/dmo/esd/evm/policy_docs.cfm).

    If we need to report costs by any means other then the WBS, then we generally code up the work packages for that purpose.

    J
  10. 0
    Jorge Taguinod ·
    My perspective of WBS and CBS are quite simple.

    WBS is how the WORK is broken down. Ergo, from the point of doing it. This is called project decomposition. Let’s say you’re the project owner and you want a hospital built. Do you just say, "Hey, I want a hospital?" Well, maybe. But then someone (if not the owner) has to to define the Product Scope (features of the hospital - will it have a spa, swimming pool, or even mini golf course?) What kind of diseases or illnesses can will it be able to serve?

    From the product features, the deliverables will then be identified. And broken down until detailed activities have been defined.

    Since all projects involve cost, Finance will have to manage the project as well. Now Finance and Engineering see the world differently. Engineers may not be very concerned about the how taxes are handled in the project, but Finance is. And these two usually break down (decompose) the project in different ways. Ergo - the CBS.

    But what do the contractors see when a work package is sent out for bidding? It depends who prepared the bid documents. If it was prepared by Finance and Legal, then the contractor would most likely see CBS.

    Primavera software has long realized this need and has developed its software to adresss the perspectives of multiple stakeholders. Stictly, it can handle:
    1. WBS
    2. Cost Accounts (aka CBS)
    3. RBS - resource breakdown structures; and Roles
    4. OBS - Organizatinoal Breakdown Structures
    5. Activity Codes and Resources Codes - user defined codes that allow you to code your project in any way imaginable.
    6. EPS - Enterprise Project Structure (allows organizations to organize projects by division, department, vision/mission/goal, etc.)

    If you’re covering the whole gamut of project management (the 9 knowledge areas) - then I’d recommend Primavera Enterprise. This piece of software is able to handle all the knowledge areas of project management, from project initiation to closure.

    Best regards,

    Jorge
  11. 0
    Milind Pandhare ·
    -----WORK BREAKDOWN STRUCTURE-----

    Structure: xxx.xx.xx.xx.xx.xx.xx.xx

    WBS Code Title

    .
    B55 B + G + 7 + H C R E S I ( B - 5 5 )
    BO1 RESI. BLDG.PROJECT
    BO1.1 KEY MILESTONE
    BO1.2 Submittals & Approvel
    BO1.2 .1 Subcontractor
    BO1.2 .2 Shopdrawing
    BO1.2 .3 Nominated supplier / Subcontractor
    BO1.2 .4 Provisional Sum Finilise By Client
    BO1.4 CONSTRUCTION
    BO1.4 .1 Mobilisation
    BO1.4 .2 Sub Structure
    BO1.4 .2 .1 Shoring Piling
    BO1.4 .2 .2 Excavation
    BO1.4 .2 .3 Dewatering
    BO1.4 .2 .4 Raft Work
    BO1.4 .2 .4 .1 PCC & Waterproffing
    BO1.4 .2 .4 .2 Rebar
    BO1.4 .2 .4 .3 MEP work
    BO1.4 .2 .4 .4 Concreting
    BO1.4 .2 .5 Basement Level
    BO1.4 .2 .5 .1 Column
    BO1.4 .2 .5 .1 .1 Rebar
    BO1.4 .2 .5 .1 .2 Form Work
    BO1.4 .2 .5 .1 .3 Concreting
    BO1.4 .2 .5 .2 Shear Wall
    BO1.4 .2 .5 .2 .1 Rebar
    BO1.4 .2 .5 .2 .2 Form Work
    BO1.4 .2 .5 .2 .3 Concreting
    BO1.4 .2 .5 .3 Slab
    BO1.4 .2 .5 .3 .1 Rebar
    BO1.4 .2 .5 .3 .2 Form Work
    BO1.4 .2 .5 .3 .3 Conreting
    BO1.4 .3 Super Structure
    BO1.4 .3 .1 Ground Floor Level
    BO1.4 .3 .1 .A Slab Work
    BO1.4 .3 .1 .A . 1 Column
    BO1.4 .3 .1 .A . 1.1 Rebar
    BO1.4 .3 .1 .A . 1.2 Form Work
    BO1.4 .3 .1 .A . 1.3 Concreting
    BO1.4 .3 .1 .A .2 Sherar Wall
    BO1.4 .3 .1 .A .2 .1 Rebar
    BO1.4 .3 .1 .A .2 .2 Form Work
    BO1.4 .3 .1 .A .2 .3 Concreting
    BO1.4 .3 .1 .A .3 Slab
    BO1.4 .3 .1 .A .3 .1 Form Work
    BO1.4 .3 .1 .A .3 .2 Rebar
    BO1.4 .3 .1 .A .3 .3 MEP Work
    BO1.4 .3 .1 .A .3 .4 Concreting
    BO1.4 .3 .2 First Floor Level
    BO1.4 .3 .2 .A Slab Work
    BO1.4 .3 .2 .A .1 Column
    BO1.4 .3 .2 .A .1 .1 Rebar
    BO1.4 .3 .2 .A .1 .2 Form Work
    BO1.4 .3 .2 .A .1 .3 Concreting
    BO1.4 .3 .2 .A .2 Shear Wall
    BO1.4 .3 .2 .A .2 .1 Rebar
    BO1.4 .3 .2 .A .2 .2 Form Work
    BO1.4 .3 .2 .A .2 .3 Concreting
    BO1.4 .3 .2 .A .3 Slab
    BO1.4 .3 .2 .A .3 .1 Form Work
    BO1.4 .3 .2 .A .3 .2 Rebar
    BO1.4 .3 .2 .A .3 .3 MEP Work
    BO1.4 .3 .2 .A .3 .4 Concreting
    BO1.4 .3 .3 Second Floor Level
    BO1.4 .3 .3 .A Slab Work
    BO1.4 .3 .3 .A .1 Column
    BO1.4 .3 .3 .A .2 Shear Wall
    BO1.4 .3 .3 .A .3 Slab
    BO1.4 .3 .3 .B Part 2
    BO1.4 .3 .3 .B .1 Column
    BO1.4 .3 .3 .B .2 Shear Wall
    BO1.4 .3 .3 .B .3 Slab
    BO1.4 .3 .4 Third Floor Level
    BO1.4 .3 .4 .A Part 1
    BO1.4 .3 .4 .A .1 Column
    BO1.4 .3 .4 .A .2 Shear Wall
    BO1.4 .3 .4 .A .3 Slab
    BO1.4 .3 .4 .B Part 2
    BO1.4 .3 .4 .B .1 Column
    BO1.4 .3 .4 .B .2 Shear Wall
    BO1.4 .3 .4 .B .3 Slab
    BO1.4 .3 .5 Fifth Floor
    BO1.4 .3 .5 .A Part 1
    BO1.4 .3 .5 .A .1 Column
    BO1.4 .3 .5 .A .2 Shear Wall
    BO1.4 .3 .5 .A .3 Slab
    BO1.4 .3 .5 .B Part 2


    BO1.4 .3 .5 .B .1 Column
    BO1.4 .3 .5 .B .2 Shear Wall
    BO1.4 .3 .5 .B .3 Concreting
    BO1.4 .3 .6 Sixth Floor
    BO1.4 .3 .6 .A Part 1
    BO1.4 .3 .6 .A .1 Column
    BO1.4 .3 .6 .A .2 Shear Wall
    BO1.4 .3 .6 .A .3 Slab
    BO1.4 .3 .6 .B Part 2
    BO1.4 .3 .6 .B .1 Column
    BO1.4 .3 .6 .B .2 Shear Wall
    BO1.4 .3 .6 .B .3 Slab
    BO1.4 .3 .7 Seventh Floor
    BO1.4 .3 .7 .A Part 1
    BO1.4 .3 .7 .A .1 Column
    BO1.4 .3 .7 .A .2 Shear Wall
    BO1.4 .3 .7 .A .3 Slab
    BO1.4 .3 .7 .B Part 2
    BO1.4 .3 .7 .B .1 Column
    BO1.4 .3 .7 .B .2 Shear Wall
    BO1.4 .3 .7 .B .3 Slab
    BO1.4 .3 .8 Roof Floor
    BO1.4 .3 .8 .1 Column
    BO1.4 .3 .8 .1 .1 Rebar
    BO1.4 .3 .8 .1 .2 Form Work
    BO1.4 .3 .8 .1 .3 Concreting
    BO1.4 .3 .8 .2 Shear Wall
    BO1.4 .3 .8 .2 .1 Rebar
    BO1.4 .3 .8 .2 .2 Form Work
    BO1.4 .3 .8 .2 .3 Concreting
    BO1.4 .3 .8 .3 Slab
    BO1.4 .3 .8 .3 .1 Form Work
    BO1.4 .3 .8 .3 .2 Rebar
    BO1.4 .3 .8 .3 .3 MEP Work
    BO1.4 .3 .8 .3 .4 Concreting
    BO1.4 .3 .9 Upper Roof Floor
    BO1.4 .3 .9 .1 Column
    BO1.4 .3 .9 .1 .1 Rebar
    BO1.4 .3 .9 .1 .2 Form Work
    BO1.4 .3 .9 .1 .3 Concreting
    BO1.4 .3 .9 .2 Shear Wall
    BO1.4 .3 .9 .2 .1 Rebar
    BO1.4 .3 .9 .2 .2 Form Work
    BO1.4 .3 .9 .2 .3 Concreting
    BO1.4 .3 .9 .3 Slab
    BO1.4 .3 .9 .3 .1 Form Work
    BO1.4 .3 .9 .3 .2 Rebar
    BO1.4 .3 .9 .3 .3 MEP Work
    BO1.4 .3 .9 .3 .4 Concreting
    BO1.4 .4 Mep Work
    BO1.4 .4 .1 Electrial work
    BO1.4 .4 .1 .1 Basement Level
    BO1.4 .4 .1 .1 .1 1st Fix
    BO1.4 .4 .1 .1 .2 2nd Fix
    BO1.4 .4 .1 .1 .3 Final FIx
    BO1.4 .4 .1 .2 Ground Floor Level
    BO1.4 .4 .1 .2 .1 1st Fix
    BO1.4 .4 .1 .2 .2 2nd Fix
    BO1.4 .4 .1 .2 .3 Final FIx
    BO1.4 .4 .1 .3 First Floor Level
    BO1.4 .4 .1 .3 .1 1st Fix
    BO1.4 .4 .1 .3 .2 2nd Fix
    BO1.4 .4 .1 .3 .3 Final FIx
    BO1.4 .4 .1 .4 Roof Level
    BO1.4 .4 .1 .4 .1 1st Fix
    BO1.4 .4 .1 .4 .2 2nd Fix
    BO1.4 .4 .1 .4 .3 Final FIx
    BO1.4 .4 .2 Plumbing & Drainage
    BO1.4 .4 .2 .1 Basement Level
    BO1.4 .4 .2 .1 .1 1st Fix
    BO1.4 .4 .2 .1 .2 2nd Fix
    BO1.4 .4 .2 .1 .3 Final FIx
    BO1.4 .4 .2 .2 Ground Floor Level
    BO1.4 .4 .2 .2 .1 1st Fix
    BO1.4 .4 .2 .2 .2 2nd Fix
    BO1.4 .4 .2 .2 .3 Final FIx
    BO1.4 .4 .2 .3 First Floor Level
    BO1.4 .4 .2 .3 .1 1st Fix
    BO1.4 .4 .2 .3 .2 2nd Fix
    BO1.4 .4 .2 .3 .3 Final FIx
    BO1.4 .4 .2 .4 Roof Level
    BO1.4 .4 .2 .4 .1 1st Fix
    BO1.4 .4 .2 .4 .2 2nd Fix
    BO1.4 .4 .2 .4 .3 Final FIx
    BO1.4 .4 .3 A/C Work
    BO1.4 .4 .3 .1 Basement Level
    BO1.4 .4 .3 .1 .1 1st Fix
    BO1.4 .4 .3 .1 .2 2nd Fix
    BO1.4 .4 .3 .1 .3 Final FIx
    BO1.4 .4 .3 .2 Ground Floor Level
    BO1.4 .4 .3 .2 .1 1st Fix
    BO1.4 .4 .3 .2 .2 2nd Fix
    BO1.4 .4 .3 .2 .3 Final FIx

    BO1.4 .4 .3 .3 First Floor Level
    BO1.4 .4 .3 .3 .1 1st Fix
    BO1.4 .4 .3 .3 .2 2nd Fix
    BO1.4 .4 .3 .3 .3 Final FIx
    BO1.4 .4 .3 .4 Roof Level
    BO1.4 .4 .3 .4 .1 1st Fix
    BO1.4 .4 .3 .4 .2 2nd Fix
    BO1.4 .4 .3 .4 .3 Final FIx
    BO1.4 .4 .4 Fire Alarm Work
    BO1.4 .4 .4 .1 Basement Level
    BO1.4 .4 .4 .1 .1 1st Fix
    BO1.4 .4 .4 .1 .2 2nd Fix
    BO1.4 .4 .4 .1 .3 Final FIx
    BO1.4 .4 .4 .2 Ground Floor Level
    BO1.4 .4 .4 .2 .1 1st Fix
    BO1.4 .4 .4 .2 .2 2nd Fix
    BO1.4 .4 .4 .2 .3 Final FIx
    BO1.4 .4 .4 .3 First Floor Level
    BO1.4 .4 .4 .3 .1 1st Fix
    BO1.4 .4 .4 .3 .2 2nd Fix
    BO1.4 .4 .4 .3 .3 Final FIx
    BO1.4 .4 .4 .4 Roof Level
    BO1.4 .4 .4 .4 .1 1st Fix
    BO1.4 .4 .4 .4 .2 2nd Fix
    BO1.4 .4 .4 .4 .3 Final FIx
    BO1.4 .5 Finishing Work
    BO1.4 .5 .1 Basement Floor
    BO1.4 .5 .1 .A Block work & Plaster
    BO1.4 .5 .1 .B Water proffing & Flooring
    BO1.4 .5 .1 .B .1 Wet Area
    BO1.4 .5 .1 .B .2 Dry Area
    BO1.4 .5 .1 .B .3 Other Area FLooring
    BO1.4 .5 .1 .C False Ceiling
    BO1.4 .5 .1 .C .1 1st Fix
    BO1.4 .5 .1 .C .2 2nd Fix
    BO1.4 .5 .1 .D Painting Work
    BO1.4 .5 .2 Ground Floor
    BO1.4 .5 .2 .1 Substation Work
    BO1.4 .5 .2 .A Block work & Plaster
    BO1.4 .5 .2 .B Water proffing & Flooring
    BO1.4 .5 .2 .B .1 Wet Area
    BO1.4 .5 .2 .B .2 Dry Area
    BO1.4 .5 .2 .B .3 Other Area FLooring
    BO1.4 .5 .2 .C False Ceiling
    BO1.4 .5 .2 .C .1 1st Fix
    BO1.4 .5 .2 .C .2 2nd Fix
    BO1.4 .5 .2 .D Painting Work
    BO1.4 .5 .3 First Floor
    BO1.4 .5 .3 .A Block work & Plaster
    BO1.4 .5 .3 .B Water proffing & Flooring
    BO1.4 .5 .3 .B .1 Wet Area
    BO1.4 .5 .3 .B .2 Dry Area
    BO1.4 .5 .3 .B .3 Other Area FLooring
    BO1.4 .5 .3 .C False Ceiling
    BO1.4 .5 .3 .C .1 1st Fix
    BO1.4 .5 .3 .C .2 2nd Fix
    BO1.4 .5 .3 .D Painting Work
    BO1.4 .5 .4 Roof Floor
    BO1.4 .5 .4 .A Block work & Plaster
    BO1.4 .5 .4 .B Water proffing & Flooring
    BO1.4 .5 .4 .B .1 Wet Area
    BO1.4 .5 .4 .B .2 Dry Area
    BO1.4 .5 .4 .B .3 Other Area FLooring
    BO1.4 .5 .4 .C False Ceiling
    BO1.4 .5 .4 .C .1 1st Fix
    BO1.4 .5 .4 .C .2 2nd Fix
    BO1.4 .5 .4 .D Painting Work
    BO1.4 .51 Carpentry & Joinery Work
    BO1.4 .51.A Basement Floor
    BO1.4 .51.B Ground Floor
    BO1.4 .51.C First Floor
    BO1.4 .51.D Roof Floor
    BO1.4 .52 Internal Decoration Work
    BO1.4 .52.A Basement Floor
    BO1.4 .52.B Ground Floor
    BO1.4 .52.C First Floor
    BO1.4 .52.D Roof Floor
    BO1.4 .6 External Work
    BO1.4 .6 .1 Elevation -A
    BO1.4 .6 .2 Elevation -B
    BO1.4 .6 .3 Elevation -C
    BO1.4 .6 .4 Elevation -D
    BO1.4 .6 .E Other Work
    BO1.4 .6 .E .1 Paving Work
    BO1.4 .6 .E .2 External Painting
    BO1.4 .7 Other Subcontractors Work
    BO1.4 .7 .1 Metal Work
    BO1.4 .7 .2 Other Provisional Item Work
    BO1.4 .8 Demobilisation & Site Cleaning

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