Immunohistochemical (IHC) staining is a good example of a complex workflow in the histology laboratory. There have been many automated staining instruments introduced on the market that stain slides by the use of a robotic arm pipetting system which applies the reagents in a controlled sequential manner. The use of automated IHC instrumentation has greatly improved the turnaround times and staining consistency over manual IHC methods. However, until recently, most automated IHC instrumentation has remained oriented to batch staining of slides into "runs" where the largest possible group of slides were stained simultaneously. Batching or staining runs have been a primary limitation on instrument throughput as these are determined by the slide capacity of each staining run. Batch processing into IHC staining runs opposes Lean single piece workflow by the creating bottlenecks, wait times, as well as introducing potential batch-to-batch variability between runs. Recently, as Lean thinking has been adopted into histology laboratories, more IHC instrumentation has been introduced which incorporates continuous or single-piece flow staining. One notable example of this adoption occurred at the Cleveland Clinic Foundation (CCF) where they were able to maintain their IHC slide staining capacity with two fewer instruments, begin their IHC staining earlier in the day, and greatly improve their turn around times in IHC, just by the adoption of a continuous process staining platform. The CCF example helps demonstrate the improvements possible with a more Lean process, even within the most complex and high-volume histology workflow.