Advances in Water Treatment and Enviromental Management

PLANT MONITORING AND CONTROL SYSTEMS 101to express interest. The pre-qualifications included a first stage questionnaireidentifying broad technical and commercial suitability. This was followedby a second more rigorous review of technical capability and quality systemswhich involved visits to the candidate’s premises and inspection of theirpractices and procedures. Also client and credit references were taken upfrom the potential suppliers.Pre-qualification resulted in a tender list of five and a tender specificationfor the Southern Telemetry Area (STA) PMCS Telemetry System was releasedin August 1989 with a period of 2 months for response.Evaluation of the five received tenders involved assessment of the technicalcompliance together with the analysis of the financial implications of variouslevels of definite and optional work. These levels were defined by the siteaudits completed to date, and schedules of anticipated procurement to beclarified during the remainder of the audit programme. To compare theseaspects of the bids a number of models of the final priced configurationwere established ranging from the minimum expected to the maximumanticipated expansion. These models took into account the cost of ownershipwhich included maintenance software licences and expansion costs. Withinthis range the mix of outstation types was varied to reflect the uncertaintyin the outcome of the incomplete audit activities. This process allowed thebids to be compared, costs assessed and the implications of the costs onthe procurement strategy to be evaluated.Arising from the telemetry specification and the tender returns for theSouthern Area, the technical solution offered is of high quality providing asystem able to meet the needs of the District Managers. Potential existswith the technical solution for expansion and enhancements without majorimplications to the PMCS investment. The system provides a variety offunctionality in outstation types including the use of third-party outstations.Five district centres are served by two telemetry computer centres using ahighly resilient configuration. Provision exists within the system for theintegration of local, on-site SCADA and control systems compatible withthe PMCS and to a defined price offered as part of the PMCS telemetrycontract. The analysis and definition of the interface to operationalmanagement systems is included as an option of the contract.Prequalifications similar to the telemetry tender exercise took place to securea select list of potential instrumentation and electrical contractors. Againsteach project 6 bidders were selected to competitively tender for the project.The implementation programme required that a significant proportion ofsites be completed prior to the telemetry system delivery and setting towork. Thus a progressive approach to site installation, testing and