- Problem Definition
One of the leading causes of claims and disputes on a project comes because of poor or incomplete scope definition; leading to scope changes and variations. Standardized WBS structures can help the project team to deliver project objective with OTOBOS (On Time, On Budget and On Schedule). What kind of standardized WBS can be adapted for Gas Station (GS) Project?
- Develop the Feasible Alternative
There are two best practice of standardized WBS:
- NORSOK Standard Z-014: Standard Cost Coding System (SCSS) rev 1, Oct 2002. NORSOK was developed on 1989 because the Norwegian government was unhappy with all their production sharing contractors reporting costs using different coding structures.
- OmniClass: The concept for OmniClass is derived from internationally-accepted standards that have been developed by the International Organization for Standardization (ISO 12006-2) and the International Construction Information Society (ICIS) subcommittees and workgroups from the early-1990s to the present.
The author will compare both of them and choose one that most suitable for GS Project.
- Develop of the Outcome for Alternative
Two standardized WBS will be compare using the Lexicography Non-Compensatory Models.
- Selection Criteria
Two standardized WBS will be evaluated considering the following attributes:
- Suitable for Onshore/Offshore
- Managing Project Interface
- No of Dimensions
- Level of Work Package Details
- Monitoring the Project
- Zone Breakdown Structure
- Analysis & Comparison of Alternative
OmniClass consists of 15 hierarchical tables, each of which represents a different facet of construction information or entries on it can be combined with entries on other tables to classify more complex subjects.
Fig 1. Inter-related OmniClass
Fig 2. OmniClass Table 21 (Elements) 
NORSOK standard describes a system for coding of cost and weight estimates and as-built/experience data. It comprises 3 sets of complementary sub-coding systems named:
- PBS (Physical Breakdown Structure)
- SAB (Standard Activity Breakdown)
- COR (Code Of Resources)
Fig 3. Norsok SAB (Standard Activity Breakdown) Elements
The WBS comparison of the attributes is expressed in Table 1 below:
Table 1. Comparison of WBS attributes
Attributes in table 1 were ranked in order of importance by applying paired comparison between each attribute combination. Results are shown as follows:
Table 2. Ordinal Ranking of WBS attributes
Table 3. Application of Lexicography
6. Selection of the Preferred Alternatives
Considering the above ranking results, the OmniClass WBS was found the optimum selection, since it has the highest score. The OmniClass is suited for the onshore projects and has the highest numbers of dimensions. Therefore, it could be adapted as a standardized WBS to enhance the project performance and cost control GS projects. The OmniClass as a multidimensional WBS is better defined and zoning the scope with in-depth level of details and ease/define the possible interface and facilitate monitoring the project comparing to the others. These advantages will contribute significantly in reducing the number of change orders as it will reduce the possible scope omissions or errors.
7. Performance Monitoring and The Post Evaluation Result
The next step will be to build up WBS for the Gas Station Project using top three elements of OmniClass, to prove whether the conclusion above is correct, and start evaluating the impact during phases of the project.
- Planning Planet (2017). Creating Work Breakdown Structure. Retrieved from http://www.planningplanet.com/guild/gpccar/creating-work-breakdown-structure
- Ardi, Satria. (2014). W14_SAS_Developing|Soroako AACE 2014. Retrieved from https://soroakoaace2014.wordpress.com/2014/12/12/w14_sas_developing-standardize-omniclass-3d-wbs-for-electric-furnace-rebuild-project/
- OmniClass (2017), OmniClass Table 21 – Elements (includes design elements). Retrieved from www.omniclass.org/tables/OmniClass_21_2012-05-16.zip
- Norsok Standard Z-014 (2017), Norsok Standard Z-014. Retrieved from http://www.standard.no/pagefiles/951/z-014.pdf
- Ardi, Satria. (2014). W12_SAS_Developing|Soroako AACE 2014. Retrieved from https://soroakoaace2014.wordpress.com/2014/11/28/w12_sas_developing-3d-wbs-for-electric-furnace-rebuild-project/
- El Rashid, M. (2016). The Influence of Non-Standard Work Breakdown Structure on Change Orders and Cost Estimation for Sudan Oil and Gas Projects, PM Word Journal Vol. V. Retrieved from http://pmworldlibrary.net/wp-content/uploads/2016/12/pmwj53-Dec2016-ElRashid-non-standard-work-breakdown-structure-sudan-featured-paper.pdf