Pipeline construction, as with other linear projects, presents construction challenges such as maintaining crew separation, equipment move-arounds, permitting, land acquisition and crossings. Ideally, you want to resolve any land and permitting issues before construction begins and then sequentially start your crews using different lags to reduce the total time in construction while preventing one crew catching up to another.
Traditional scheduling tools such as Microsoft Project or Primavera do very little for planning and executing pipeline construction if you want to consider these construction issues. These tools, in particular, do not show which part of the project has been completed, where the crews are in relation to each other and what other factors are important to the successful completion of the project.
For each task, the start and end date and the physical percent complete are readily displayed using these tools. We can see that grading is about 18% complete, welding about 13% complete etc. No further information where work was done is added.
In the example below, during execution of the project there was no access to land in section 10 000 to 12000 and the crews had to move to station point 15 000.
Although there was no delay of finishing the project, the execution was quite different than planned. The baseline is shown as brightly coloured lines.
In the TILOS distance Gantt chart, the executed sectors and the progress situation can be easily be monitored.
Earned value calculations, such as the schedule performance index (SPI) show a comparison of planned durations against actual ones. Grading has more progress than planned for the report date, but due to earlier start the schedule index is smaller than 1.
Using traditional planning systems, this work could only be done by splitting tasks into sections (e.g. of 1 km) and then reporting progress on these sections. This makes the creation and linking of tasks more complex so that, for example, in a 100 km long pipeline project, 800 tasks need to be created. The reporting needs to be done specifically to the planned task using its ID. If a crew reports progress from 1800 to 3200 then this needs to be converted into 3 tasks.
Including weather forecast
Weather is an important factor in determining the productivity rate of crews during pipeline construction. Rainy seasons affect crew productivity and accessibility to the right-of-way. In a TILOS chart a meteorological map can be added to the view so that the weather risk can be mitigated during the planning phase.
As a consequence of weather analysis, the project was broken into 2 spreads. First the section between KP 80 and KP 260 were done in order to work in that area during the dry season. All crews and equipment were moved to KP 0 to complete the remaining 80 km.
The extra mobilization costs were compensated by the higher performance of the crews in the dry season within the mountain area.
BAKU-TBILISI-CEYHAN P.L. PROJECT
This plan was created in TILOS and shows a 280 km section of this project. Further information regarding this project can be found in http://en.wikipedia.org/wiki/Baku-Tbilisi-Ceyhan pipeline.
In this example, the distance axis is vertical and the time axis is horizontal like a Gantt chart. The distance axis description shows in each section the link to the relevant drawings, the KP, the elevation and also a description for each important KP.