ÂWho does what is critical. ExxonMobilÂs Timm Madden stressed the importance of well-documented scope definition and management under the MAC methodology. |
Scope definition and management is critical to success, said Madden. ÂWho does what is critical, he explained. ÂThe skill sets are variable among both MACs and EPCs, but weÂve never selected an EPC based on its I&C skills. And by now we have a reasonably large and diverse MAC database from which to derive lessons learned.ÂMadden warned, however, that although demand is currently great for engineers, thatÂs not necessarily good for MACs and EPCs because engineers often find a better arrangement elsewhere mid-project. ÂMaintaining a qualified workforce is difficult, he said.
Madden, Day and Reid-Bicknell all agreed that data coordination is another potential hazard to the project. ÂMore and more, weÂre compressing our schedules, said Madden, Âso the I&C data that is developed by the EPC and needed by the MAC is frequently late. In the ExxonMobil development plan, we include all deliverables to and from the MAC in the EPC and the MAC schedules. These two schedules need to dovetail together.Â
Other potential problemsÂknock-on effects of late facility design changes and the impracticality of integrated FAT because of multiple EPCsÂwere identified by Madden. ÂMost large projects have many interfaces, and many of those are with the MAC, said Madden. ÂThe I&C chain of command isnÂt always clear, and packaged vendor support and I&C technicians often are not available. Sometimes EPC process design engineering isnÂt even available.Â
From the ownerÂs perspectiveÂin this case, ExxonMobilÂsÂhow willingly have EPCs accepted the MAC concept? ÂMany EPCs have figured out that MAC concept is a good thing for them, claimed Madden. ÂInitially, there were a lot of complaints. But the hours that the MAC is taking away are the high-risk hours, and the work isnÂt among the EPCÂs core competencies. The MAC concept is still in evolution. Eventually, this will be the standard way of operating.Â
Both Day and Reid-Bicknell agreed with Madden that integration of the EPC and MAC schedules was important to project success. But each had a slightly different take on some of the other critical factors. Where Reid-Bicknell encouraged direct contracting between the MAC and the client and early definition and scheduling of the MAC role in the commissioning and startup, Day emphasized the EPCÂs need for a change management plan and the impact of EPC and MAC disbursed execution.
 ÂA detailed responsibility matrix for the owner, EPC and MAC needs to be developed, said Day. The more detailed, the better. ÂWe prefer an execution strategy that promotes the EPC having direct control of its own destiny. You need to ensure the selection process emphasizes evaluation of the MACÂs proposed execution plan, execution organization and infrastructure. For some reason, one of the most difficult things to do is to fully integrate the MAC and EPC schedules.Â
Day agrees with Madden on the need for coordinated schedules. ÂWe understand the tug of war over hardware and software data and deliverable freeze dates, said Day. ÂThe MAC wants that data earlier, but as an EPC, we often have difficulty meeting those dates. Any changes after the freeze dates create a commercial implication. ItÂs a good idea to just plan for change. IÂve never been on a project where we didnÂt have change.Â
In the end, however, owner/PMC oversight is required to audit consistency across multiple EPCs and to intervene should differences arise between a MAC and an EPC, said Day.
ÂThe MAC model has become the model for large projects or for projects with multiple EPCs, asserted Reid-Bicknell. Emerson has executed more than 50 MAC projects, and Reid-Bicknell explained there are four main typesÂthose contracted by a third party; those contracted by the client/EPC; those contracted by the EPC; and direct to client, the preferred type.
ÂThe MAC needs a clear identification of deliverables critical in scope definition, he said.
The benefits of the MAC outweigh its disadvantages. ÂExtensive interface agreements must be established when dealing with multiple locations, and there are no contractual obligations for the EPC and MAC to work together, so it takes some extra effort to create that kind of teamwork, explained Reid-Bicknell. ÂBut using a MAC eliminates some of the bid packages, and it ensures that the automation system is consistent with the clientÂs vision as defined in the FEED [front-end engineering and design], and that the automation vendor is substantially more responsive to the clientÂs need and vision. Plus, the MAC can offload some of the workload and provide leadership with interface management plans.Â