Process variability secretly diminishes product quality. But where is the source?
The single biggest source of quality problems in plants, mills, and refineries is process variability. And while typical causes of variability are normal aspects of any operation, they often go undiagnosed.
Variability can originate anywhere; from sticking control valves to drifting transmitters, from poorly tuned manual loops to excessive vibration in rotating equipment. Individually, these variations may be minor. Together, they can propagate and increase your costs by increasing off spec product and rework. Imagine if your assets could tell you when they were operating out of range... so that you could take action before quality is compromised?
The Solution: PlantWeb predictive intelligence helps reduce variability
PlantWeb architecture helps you reduce off-spec product and other quality problems by using its predictive intelligence to reduce process variability.
How? Our technology and services enable you to see what's happening in your process, predict and identify conditions that cause variability, access the information wherever it's needed, and take action to maintain or improve quality … before it's too late.
Reducing variability starts with choosing accurate, reliable valves, and instruments - such as our transmitters with fast dynamic response and 5-year "set and forget" stability - and then using embedded diagnostics to keep them delivering the performance you need. For example:
Valve signature diagnostics in Fisher FIELDVUE digital valve controllers detect performance changes caused by stiction or other problems, so you can determine how much a valve may be affecting variability and schedule service before quality suffers.
Sensor fouling detection in Rosemount analytical devices identifies fouling that can lead to inaccurate measurements and off-spec product.
Adaptive digital signal processing in Rosemount vortex flowmeters tracks the signal and makes adjustments to reflect process conditions, so setpoints aren't subject to analog drift.
The benefits aren't limited to valves and instruments. PlantWeb diagnostics based on statistical process monitoring can identify a wide variety of potential problems - from leaks in pipes to fouling in heat exchangers, filters, and similar equipment.
Enabling better control
PlantWeb also helps you maintain tight, accurate process control that reduces variability -- and can even enable set-point shifting for higher-quality output.
Our FOUNDATION fieldbus devices constantly check for problems and label the data they send as good, bad, or uncertain. PlantWeb’s DeltaV or Ovation automation system monitors this status information and can automatically modify control actions if the status changes - so you never control off bad data.
PlantWeb helps reduce variability even more through advanced control. These integrated functions have access to the same validated process and equipment data that's available to the rest of the architecture. For example,
The multivariable Model Predictive Control technology in DeltaV Predict [PDF] software uses powerful but easy-to-use function blocks to deal with excessive dead time, long time constants, and loop-to-loop interactions.
DeltaV Inspect [PDF] software can locate existing variability in a control loop, as well as individual instruments and valves, or notify an operator if variability exceeds limits.
Ovation Tune software smoothes out variability by monitoring and adaptively tuning loops for optimal performance—not just at startup, but also during ongoing operations.
Maximizing the advantages
Emerson offers a wide range of services to help you make the most of the architecture's quality-improvement capabilities -- and sustain the gain throughout the life of the plant. Our Entech Process leverages our process equipment expertise to deliver custom control solutions, training for optimal operations, dynamic simulations using real process data, and tuning and analysis software for data gathering and analysis.
Better quality means lower waste
The cost of poor quality is two fold: first, you have the lost opportunity cost of unsaleable product with off spec product. Secondly, you have the very real cost of wasted raw materials, wasted energy plus disposal costs. By reducing variability, and improving quality, waste & rework become a thing of the past.
The Proof
Download a free white paper for an in-depth discussion of quality improvement with PlantWeb architecture. Now available in multiple languages!
Download a free white paper for an in-depth discussion of quality improvement with PlantWeb architecture. Now available in multiple languages!
