W6.1_TH_ Standardized WBS Structures for Gas Station Project-Part 3

1. Problem Definition

After compare two best practice of standardized WBS on Blog W2 and W5, this week the Blog will determine and analyze which of the 15 elements Omniclass tables would be applicable to use in creating a WBS structure for a Gas Station Project.

2. Develop the Feasible 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[2].

Fig 1. Inter-related OmniClass[2]

Author will be chosen what kind of tables on OmniClass that applicable for GS Project WBS.

3. Develop of the Outcome for Alternative

To choose top four most applicable tables from the 15 tables, the most appropriate technique will be the multi attributes approach. Compensatory models, the additive weighting technique has been chosen to help performing the comparison and selection. In all compensatory models, which involve a single dimension, the values of all attributes must be converted to a common measureable scale. By using determined criteria related to the Gas Station Project, the additive weighting technique will rank the 15 tables, shows high to low applicability and relevance to the project.

 4. Selection Criteria

There are six criteria related to gas station project that have been determined for the OmniClass tables selection:

  1. WBS zone that related to Gas Station Project (1-3, 3 being highest relationship)
  2. WBS deliverables related to Gas Station Project (1-3, 3 being highest relationship)
  3. WBS activity related to Gas Station Project (1-3, 3 being highest relationship)
  4. WBS organization that related to Gas Station Project (1-3, 3 being highest relationship)
  5. WBS level detail completeness (1-4, 4 being preferable)
  6. Tables applicability/uses for oil & gas project (low to high)
5. Analysis & Comparison of Alternative

The comparison result of OmniClass Tables is shown in the following table:

Table 1. OmniClass Tables Comparison Based on Six Selection Criteria

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 OmniClass Tables attributes

Based on Table 2, relative rank = ordinal rank + 1. A rank of 5 is best, the relative ranking will become as follows:

Table 3 OmniClass Tables Selection – Attribute Weight

The attributes values on Table 1 have to be converted in to non-dimensional form. The procedure for converting the original data on table 1 for a particular attribute to its dimensionless rating is:

The non-dimensional (dimensionless) values of the attributes are shown on Table 4:

Table 4 OmniClass Tables Selection – Dimensionless Value

Finally, for each OmniClass table, the normalized weight of the attribute (Table 3) is multiplied the non-dimensional attribute value (Table 4) to obtain a weighted score for the attribute. These weighted score are then summed to arrive at an overall score for each OmniClass table. The result is shown on Table 5.

Table 5 OmniClass Tables Selection – Weighted Score

6. Selection of the Preferred Alternatives

Based on calculation and Table 5 comparison, the top four most applicable and relevant WBS from OmniClass for the GS Project is:

  1. Table 13-Spaces by Function (score 0.397)
  2. Table 23-Products (score 0.357)
  3. Table 31-Phases (score 0.270)
  4. Table 33-Disciplines (score 0.254)
7. Performance Monitoring and The Post Evaluation Result

A standardized WBS structure is one success key for project team to the deliver project with OTOBOS. Next week, author will try to build up Gas Station WBS from top four OmniClass Tables, to prove whether the conclusion above is correct, and start evaluating the impact during phases of the project.


  1. Planning Planet (2017). Creating Work Breakdown Structure. Retrieved from http://www.planningplanet.com/guild/gpccar/creating-work-breakdown-structure
  2. 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/
  3. OmniClass (2017), OmniClass Table 21 – Elements (includes design elements). Retrieved from www.omniclass.org/tables/OmniClass_21_2012-05-16.zip
  4. Norsok Standard Z-014 (2017), Norsok Standard Z-014. Retrieved from http://www.standard.no/pagefiles/951/z-014.pdf
  5. 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/
  6. 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
  7. Gannasonggo, Gustaf. (2012). W3_GGS_OmniClass WBS|Casablanca AACE 2012. Retrieved from https://aacecasablanca.wordpress.com/2012/02/06/w3_ggs_omniclass-wbs-table-selection-using-additive-weighting-technique/