AVOIDING THE POTENTIAL PITFALLS OF A THIRD PARTY DISTRIBUTED CONTROL SYSTEM PROVIDER

摘要

The City of San Diego Metropolitan Wastewater Department (MWWD) is responsiblernfor treatment of wastewater from San Diego and fourteen neighboring agencies. ThernSouth Bay Water Reclamation Plant (SBWRP) is a component of MWWD抯 $1.5rnbillion Clean Water Program (CWP) capital improvement plan, developed to bring thernagency in compliance with the Clean Water Act. To implement a system-widerninstrumentation and control system for the CWP facilities, MWWD established thernClean Water Operations Management Network (COMNET). MWWD contracted with arnsingle control systems provider (CSP) to provide instrumentation and control systemsrnfor all of the CWP facilities. Contracts for construction of the various wastewaterrnfacilities are awarded via the public bidding process. The work of the CSP contractrnand the construction contract must be integrated for proper operation of the facility.rnWith a third party control system provider involved in construction of a wastewaterrntreatment facility, there is a high potential for cost growth and delays during thernconstruction phase due to conflicts between the work of the construction contract andrnthe parallel control systems contract. This paper provides some suggestions forrnmanaging the risk associated with a third party control systems provider from thernperspective of a design project manager (owner or design engineer). Thesernsuggestions are based on experience with the MWWD抯 COMNET program as it hasrnbeen implemented for the SBWRP, and generally involve limiting the extent ofrninterfacing and coordination required between the two contracts and establishingrnspecific contractual obligations for those situations where such interfacing andrncoordination is unavoidable. This paper focuses on providing additional effort duringrnthe design phase to ensure that the DCS system is effectively and efficientlyrnimplemented and to avoid potentially significant cost and schedule impacts due torninadequate coordination between the construction contract and the controls systemrncontract.