The principles of lean manufacturing have been slow to migrate to laboratories because they are quite different from manufacturing environments. While most of the key principles of traditional Lean still apply, there are many unique challenges involved in effectively implementing them in laboratories. Compared to manufacturing environments most analytical and microbiological laboratories have a relatively low volume of samples but a high degree of variability and complexity. Many standard lean tools are not a good fit, however Lean can be applied to labs. A generic approach is not suitable for laboratories but careful adaptation of the techniques based on a thorough understanding of Lab operations will deliver significant benefits in terms of cost or speed or both.
To deal with the long lead times, ‘Fast Track’ systems are often developed in an effort to deal with urgent samples but these often become unworkable. Frequently, the proportion of samples designated as priority becomes so large that ‘fast tracking’ quickly becomes ineffective.
Laboratories often maintain high levels of work in process (WIP) which inevitably results in lots of (non value adding) effort being expended in controlling, tracking and prioritizing samples and in planning analyst work. Companies often respond to this situation by investing in a "Laboratory Information Management System" (LIMS) or some other IT system. However these systems do not in themselves improve performance. The underlying process by which work is organized and moves through the lab must first be re-engineered based on lean principles.
For many testing laboratories the incoming workload is inherently volatile with significant peaks and dips. This causes low productivity (during dips) and/or poor lead time performance (during peaks). Very often the capacity of the lab is not well understood and there is no mechanism to level or smooth the workload.
The first step in designing any Lean laboratory is to specify value. Every activity in the laboratory is identified and categorizing as ‘value add’, ‘non value add’ (from the customers perspective) and ‘incidental’. Incidental work is non value add in itself but essential to enable ‘value add’ tasks to be carried out. A significant focus of any Lean Lab initiative will be to eliminate or reduce the non value add activities.
Another key Lean step is to develop value stream maps of the overall release process. This should avoid the error of working on point solutions that only end up moving a bottleneck to another process and therefore do not deliver overall improvements. For example, there is no real value in reducing analytical laboratory lead times below the time of a release constraint test in the Microbiology lab. You can however use increased velocity to help ‘level the load’ or to maximize individual test run efficiency.
A Lean laboratory will normally have a defined sequence of tests and associated analyst roles that make good use of people and equipment. A key principle is to flow work through the laboratory so that once testing begins on a sample, it is kept moving and not allowed to queue between tests. This creates a focus and drive to reduce ‘through-put’ time which can be converted into a lead-time reduction or used to allow samples to wait in an incoming queue to facilitate level loading and /or grouping for efficiency.
‘Pull’ is interpreted as testing according to customer priority. If this is not inherent in the order in which samples arrive, then the samples are taken from an incoming queue according to customer demand and thereafter processed in FIFO order with no overtaking.
At its simplest, leveling the load (overall workload) and the mix (the mix of sample types) is about putting the same amount of work into the lab on a daily basis. This is probably the most critical step and potentially the most beneficial for the majority of testing Laboratories. Successfully leveling a volatile load and mix will significantly improve productivity and/or lead time. The productivity improvement can be used to provide additional capacity or converted into a cost reduction.
Lean laboratories continuously look to develop solutions and re-engineer processes to eliminate or reduce the non value add and incidental tasks identified when ‘specifying value’.
An essential part of Lean in the Laboratory is to manage and review labs performance daily, ensuring that Key Performance Indicators (KPI's) are good and that the overall laboratory process is ‘in control’.