Muda (waste) is any activity that doesn't add value to a process or product. The 8 wastes in Lean are:
- Transportation - movement of material
- Inventory - use of space and funds to hold inventories of material
- Motion - movement of people
- Waiting - queuing or scheduled delays
- Overproduction - producing more than necessary – in lab terms this could be media, buffer or other reagents
- Over processing: excess work or checks in process
- Defects: work (samples) that needs correcting or repeating
- Skills - unused talent or potential
Muri (overburden) is the overloading of people or equipment. Muri is often directly caused by unevenness (Mura) when lab analysts are overloaded by peaks in the workload. Muri can be alleviated by effective resource scheduling levelling the workload to meets demands.
Mura, Muda and Muri operate in synchrony. Eliminating one also eliminates the others. Identifying all aspects of waste is critical to lean implementation. Value Stream Mapping (VSM) is a powerful tool for process improvement. Similarly, statistical process control charts can help evaluate process efficiencies and identify 'special causes' or anomalies within a process. SPC charts can help assess variations within a process. It is most applicable to upstream and downstream bioprocessing, however SPC can also be effective in evaluating throughput efficieincies in laboratory sampling and may be valuable in detecting variation in analytical processes. Check out the case study Statistical Process Control (SPC) and Catalent.
Process Control Chart
SPC chart outlining the upper (UCL) and lower (LCL) control limits. Generally time or sample number is on the X axis and analytical or process parameter on the Y axis