Sample Pipeline Construction Project WBS for Refinery/Chemical Plant

Sample WBS for piping construction project for a refinery or chemical plant may be organized as the following. It is worth to be organized by location wise (i.e. platform and pipe rack, platform and equipment around piping) prior to “Phase” WBS. Timely completion of piping construction is not only depending on timely receiving of engineering drawings and materials from Owner/EPC Contractor but timely availability of the infrastructure should also be addressed. Sometime it refers to work front availability. Developing WBS is mainly depending on the project scope. It should be defined according to the project specific as every project is different, for instance, “Demolishing” WBS may also be added under “Phase” level priority to “Installation” WBS if your project scope involved a considerable amount of piping demolishing scope. “Above Ground” and “Under Ground” WBS can be left in case no underground piping work is included in the project.

Oil and Fuel Storage Tank Construction Project – Sample WBS

Oil and Fuel Storage tanks (API 650 design) are typically used in petrochemical plants. They are large field fabricated storage tanks operating at low pressures or atmospheric pressures. There are various types of tanks such as fixed roof tanks and floating roof tanks, etc. Tank bottom is usually constructed of overlapping steel plates welded by manual or automatic welding technique. Tank shells are constructed from courses of steel plates. E.g. First shell course, 2nd shell course and so on.

In this article, we will focus on a specific type of tank, external floating roof type with single deck and internal pontoon. Sample Work Breakdown Structure (WBS) for an external floating roof type designed tank construction project can be decomposed as the following. As tank erection work is only focused, detailed WBS for foundation work is intentionally left at level 1.  It is just to show that foundation is required for the above ground storage tank.

Sample P6 Schedule Layout for Top 3 Float Paths

Once a suitable network has been developed, with duration and resources assigned to all activities, it is necessary to review the longest path through the project before baseline schedule is established. Scheduling Software will simply tell you where the longest path or critical paths are. Normally, a critical path should be extended from the beginning to the end of a project. Review the longest path or critical path(s) using float path layout and validate those activities on critical paths with project team to ensure it makes sense to them.

It is not easy to analyse critical path activities in case you have more than three thousand activities in your project. By having float path layout, the most critical activities or nearly critical activities can be easily reviewed to identity high risk activities when schedule risks are assessed.

When project is under way, these activities can be thoroughly reviewed with contractor and prioritized to take corrective action as defined using this float path layout. As this layout is important especially for project management team, it may be used as part of monthly or fortnightly report.

Sample Layout to Find External Links and Broken Logic

Activity with no predecessor or successor in the schedule does not drive the whole project. With the exceptional case, there may be some activities without predecessor or successor such as project start milestone, project finish milestone and an external link activity such as civil work completion of other project.

For example; equipment delivery on site date (equipment supplied by Owner/EPCm Contractor) could be an external link if you are a Constructor with both of you and Owner/EPCm schedule are internally linked. A quick way to identify the broken logic and external date activities is to create a layout and run the report as and when required.