You are the Instrumentation Manager of plants that make use of both PLC/SCADA and DCS technologies for basic process control. One of the plant PLC’s is overdue for replacement. You have already started experiencing hardware failures on this PLC. The PLC spares are obsolete and there is no technical support for this type of PLC, because it is legacy equipment. The process controlled by this PLC is batch-like in nature and the plant operates for only 8hrs out of a 24hr day. The product produced is extremely hazardous and regulated through legislation. After months of project work, the technical team proposes to replace the PLC with a full blown DCS.
What factors (both technical and non-technical) would you consider to either endorse or reject this decision? Please elaborate with facts and clearly state any assumptions made to support your case.
What factors (both technical and non-technical) would you consider to either endorse or reject this decision? Please elaborate with facts and clearly state any assumptions made to support your case.