OEE Overall Equipment Effectiveness and Cycle Time / Takt Time
OEE = Availability x Performance x Quality
Batch manufacturers often just use Cycle Time or Takt Time for the bottleneck in each process and metrics are created around that number to ensure that processing is on track. Not much time is spent on calculating the three components of Overall Equipment Effectiveness (OEE) for batch – Availability, Performance and Quality.
Shopfloor-Online™ Lifescience Edition makes it easier to calculate the sub components of OEE for batch manufacturing so that a clear picture is visible as to where the current issues are, on a real time basis. Shopfloor-Online™ Lifescience Edition will calculate OEE automatically for batch processing, to give users visibility and clarity as to where to concentrate efforts. For example, is there an issue with availability or performance or quality or all of them?. This visibility leads to better targeting of efforts in scheduling, maintenance or quality management, to ensure that customer orders can be met (>85% OEE).
Taking a closer look at each of the three components of OEE, it is understandable how OEE for batch can be perceived as complex. However, Shopfloor-Online™ Lifescience Edition makes it easy – and automatic.
Availability = 100 x Operating Time Planned Production Time = 100 x (Planned Production Time – Downtime) (Batch Duration – Scheduled Time)
Operating Time can be derived from the scheduler in Shopfloor-Online™ Lifescience Edition or from another system such as ERP or a process control system.
Planned Production Time is the Batch Duration minus the Scheduled Time. The duration of the batch can be calculated from batch event data and status changes. Shopfloor-Online™ Lifescience Edition can interface to control systems to get this information from a file or via OPC. Downtime can be calculated by Shopfloor-Online™ Lifescience Edition using state changes such as Aborted, Stopped or Held in order to calculate the actual Downtime for process units and subsequently process cells in line with S88. The scheduled time is the time between a batch being scheduled and the time it goes to the running state.
Performance = 100 x Total Product Quantity Theoretical Product Rate x Operating Time
The Total Product Quantity is usually X kg. This value may be automatically retrieved via OPC, from the batch events, ERP system or LIMS. Alternatively, users can enter this figure manually.
The Theoretical Product Rate is typically measured in kg/hr for batch processing. This is a rate against the entire process as the product may be in solution during many of the processing steps.
Operating Time = (Planned Production Time – Downtime) Quality = 100 x Actual Product Yield (or Concentration) Target Product Yield (or Concentration)
Where do we get the values?
For primary pharmaceutical processing, actual and target yield numbers can be used by Shopfloor-Online™ Lifescience Edition to calculate the quality metric.
For biological processes, the average actual product concentration and target product concentration can be used.
These values may also be automatically retrieved by Shopfloor-Online™ Lifescience Edition via OPC, from the batch events, ERP system, LIMS. Alternatively, users can enter this figure manually.