Lancon explains that it is possible to “overinvest in reliability.” A high level of reliability, as measured by mean time between repairs, can often be justified in sectors like petroleum refining, where throughputs are large and equipment runs nonstop. But in other sectors, a run-to-failure mode might be more economical, especially when the process has been designed with in-place backups.
Based on the extent of services a client seeks, Flowserve will locate personnel permanently onsite or bring in the technical expertise as needed. By starting with a comprehensive view of the plant’s assets, a fixed-fee contract can be established to maintain a certain level of uptime performance or to keep maintenance costs to a minimum.
At last fall’s ISA meeting, Invensys Process Systems rolled out a new bundle of services that it calls Lifetime Performance Services. Three were added at that time: loop management, alarm management and site security hardening. In some cases, elements of these programs are identical to hiring a consultant to provide a certain capability and then to go away. In other cases, however, the service contracts involve lengthy plant assessment studies, followed by periodic servicing. At large facilities, the service could require onsite personnel on a permanent basis.
Loop management is a good example of the latter. “Numerous surveys have shown that only 20%-30% of the control loops at a typical plant stay tuned so that they provide effective control,” says Invensys’ Spencer. “If a company has cut back on the dedicated workforce to provide continuous loop tuning, we can come in and provide this service. Additionally, we help analyze which loops are critical to control functions like advanced process control. Those are the loops that get the closest attention.”
Similarly, alarm management warrants steady attention. Operators typically deal with thousands of nuisance alarms on a daily basis; alarm messages can crop up as a control system’s software gets updated or expanded. Invensys has adopted the alarm management principles of the Engineering Equipment and Materials Users Association, London.
The third new service, site security, addresses both physical security and cybersecurity. Spencer says that chemical companies have an important decision to make regarding plant-based information networks: to depend on the security efforts coming from corporate IT departments or from control vendors. “Site security to an IT department usually means being able to detect intrusions [most IT people I’m sure would argue with that and say that they pay great attention to prevention],” he says. “To us, it means physically preventing an intrusion, by installing appropriate firewalls, security protocols and the like.” Once a site assessment has been performed and security measures installed, the system needs to be regularly maintained as modifications occur in the control system or the information network that connects to the control system.
At Emerson Process Systems, Austin, Texas, wrapping control equipment sales in a comparable set of services has long been the norm. According to William Robertson, director of worldwide services, the activity is growing from a base of providing conventional startup and commissioning services to providing “high-level consultative services” involving advanced process control, simulation modeling and the like. One version of this service offering occurs in PlantWeb, Emerson’s broad architecture for process control and plant management. A component of PlantWeb is the Asset Management Suite (AMS). According to Robertson, a client might acquire AMS, then hire Emerson not only to install it, but to set up the diagnostics to monitor equipment condition, recommend maintenance-management procedures and develop control methodologies to maximize performance or reliability. Further, Emerson provides a Web-based portal that can be customized to the client’s information needs. “The goal,” says Robertson, “is to address the total cost of ownership of the assets and not merely to maintain them.”