Interface management plays a large part in the success of managing a project. Without proper interface management, it can cause overall project to delay and cost to over run.

In construction project, there are much interface works with adjacent contractors, sub-contractors, systems wide contractors and external authorities.  Let examine some of the challenges in interface management.

Scale and Complexity of the project

One of the reasons managing large scale project is more complex is not just because the physical quantity of work is larger, but there are also more parties being involved.  Hence with more parties involved, the complexity of interfaces increases.

In a mega project, project is broken down into multiple main packages. In addition, many major trades will be appointed by the client directly and novate to the main contractors later, so as to save cost through bulk purchase and standardisation of equipment. As such, main contractors not only have to manage lateral  interfaces with the adjacent main contractors but also vertical interfaces of sub-contractors.

Inconsistencies in tender/contract documentations

It is not uncommon to find discrepancies in contract documentations between different contract packages. In one case, the nominated sub-contract stated that the duration of installation and testing of lifts was 4 months. However, in the main contracts, the duration for lifts  installation and testing allowed for only 3 months. Just imagined if you were the nominated sub-contractor, would you agree to a shorter duration upon novation to the Main-contractors?

In another example, the drawing details of the interface between adjacent contractors differed. Either contractors would not agree to change their own design as they were doing according to the required specifications. In which case, the Engineer had to issue EI to regularise the inconsistencies.

Lateral interface management.

Lateral interface refers to adjacent contractors sharing common interfaces. They don’t have direct contractual obligation with each other.

One of the common issues of lateral interfacing is sharing of access or providing of access to his adjacent contractor.  In one of my project, my contractor could not delivered materials into the bored tunnel from our side as the opening had been closed. As a result, my contractor needed to deliver the materials through the shaft opening of the adjacent contractor. As the delivery would affect their adjacent contractor’s work and there was no stipulated clause that the contractor needed to provide free access to the adjacent contractor , it took quite an amount of effort to interface and coordinate among the contractors. At times, it required the client PMs to step in to facilitate the coordination.

Other common issue of lateral interfacing work includes managing common access of the adjacent contractor to carry out their work.

In the interface zone, when there is a shared boundary or overlapping of work,  the boundary’s scope of work can be muddy. This may result in the adjacent contractors doing nothing in this interfacing zone as both contractors thought that it is the other party’s obligation.

For M&E work, it is not practical to terminate the utility work such as piping/cabling exactly at the boundary line. Hence the termination of M&E services may encroach into the other contractor’s boundary.

Vertical Interface management

In the case of vertical interfaces, the downstream contractors work depends on the successful handover of work from the upstream contractors.  If the upstream contractor cannot fulfilled his contractual obligation on time, then it has a knock off effect on the commencement of downstream contractor’s work.  

M&E systems integration

There are many M&E systems in a building which are managed by different vendors. There are much software and hardware components between systems to be integrated. Some systems adopt open standards while some systems adopt proprietary format. Hence interfacing and integrating of systems can be quite challenging and time consuming.

I saw many times the main contractor underestimate the complexities of systems integration and it took much longer time to troubleshoot and fix the faults during integration testing than planned.

 It is imperative that overall systems architecture be clearly defined and systems boundaries demarcated. Otherwise, time can be wasted on abortive work, troubleshooting and fixing the issues during testing and commissioning.

Conclusion

In summary, interface management needs careful consideration. It is important to realise this as one of the project risks and to manage it closely and timely.               

About the Author:

Stanley Tey has more than two decades of project management experience after graduating from the National University of Singapore in Civil Engineering. He also obtained a Master Degree in Software Engineering from Institute of Systems Science, NUS where he specialized in Project Management and Systems Integration.

He has worked as a Consulting Engineer, Project Planner, and Project Manager. Some of the projects he had handled are:

• North East Line
• Singapore 1st Desalination Water Plant at Tuas
• Integrated Resort Project at Sentosa
• Lonza Cell Therapy Plant at Tuas (Phase 2)
• Merck Junumet plant at Tuas
• Singapore Special Cable Tunnel Project