Lean Six Sigma Value Stream Mapping (Theory + Case)

#Lean Six Sigma Value Stream Mapping (Theory + Case)

You may wonder what all the flows and diagrams are about. It’s a value stream map! In Lean Six Sigma, we really love putting these down on flipcharts and post-its. For a good reason though; it promotes cherry picking.

The theory

Value stream mapping is one of the most-used Lean Six Sigma tools. It’s the process where a representative supply chain from supplier to customer is mapped. This is done in close cooperation with stakeholders such as Production, QA, Logistics, and Planning. Data on the process, like process steps, lead time, waiting time, inventory, # of operators, is collected and presented in visually.

Based on this map, you select projects that you think will offer the highest added value. Basically, it assists you and your company in selecting the best improvement projects. In addition, it results in a concrete understanding of all key stakeholders how everyone’s tasks and responsibilities interrelate with those of others. Value stream mapping has two main elements: preparation and data collection.

Preparation is everything.

Having a sponsor in place and with whom you agree upon the scope of the value stream mapping and who should participate in it.

Tip: Don’t step head over heels into a complex issue.

Start with a small process first, a simple and stable, preferably one product, and later on you may extend to other products and customers. It’ll probably be an eye-opener how many opportunities for improvement you can identify. Might even turn out that the process isn’t as stable as you thought it to be. Some examples of good starters for pharmaceutical companies are:

  • Bulk tableting (or filling vials), packing and shipping to customers
  • Receipt of goods, storage, order picking and shipment
  • Ready-to-use preparation of medication at hospital pharmacies

Next step: collecting data.

This may be a cumbersome task. If you collect too much, your team may be pretty critical. And if you collect too little you’ll probably encounter the same problem. So, what kind of data are we looking for? Remember that the objective of a value stream mapping is identifying waste and determining where in the process an improvement is most effective. It is after all, not for the sake of collecting data and making impressive charts (and putting them on flip-charts). It’s usually best to go out and actually observe together with your team what’s going on in your processes. Some examples to get you started:

  • Cycle time –time needed to do something in a process, e.g. vial filling and packing
  • Lead time –total time needed for a process, including waiting time as well (which is waste in lean)
  • Metrics like the number of people involved, shifts, transportation distance, and type of equipment, etc

The case


One of our customers requested us to do a mapping of one of their production processes. They chose a process which they considered to be pretty much stable. The team consisted of more than 10 people from production (media preparation, drug substance, drug product and packing), logistics, warehousing QC and QA.


First of all, all process steps were mapped, from the receiving of materials until their shipment to customers. Based on this map, we decided what data to collect.


After the data collection, the first job was to “validate” the data. A critical step, to make sure that your decisions are data-driven rather than subjective thought like: “I really think that…”, “I believe that...”, “I strongly feel that…” etc. Decisions based on the latter aren’t usually the most constructive kind.


Next up, we had brainstorm sessions for each of the steps we determined, e.g. for drug substance preparation:

  • What/who are: supplier, input, process, output, customer (in lean: a SIPOC)?
  • Which step is rate limiting?
  • Where is the waste in the process (in lean: TIMWOOD – transport-inventory-motion-waiting-overprocessing-overproduction-defects)
  • What are the top 3 improvements we can identify?

Tip: Organise a kaizen for validating the data with the team and determine where to improve.

Together, we collected our top 3 improvements and voted for a final list of priorities and actions to be improved upon.  And you may expect this from a lean fanatic, like me. But what did the team say?

“Very positive:  can only become better”

“Brings a lot”

“Nicely shows the interactions”

“Excellent overview of the specific supply chain”

 “Working together”


Finally, we presented the whole workshop planning, process, and outcome to senior management, by showing them around in the meeting room filled with flip charts.

So, what did it show? A lot! You may have noticed the triangles on the map. They represent waiting time/storage and, therefore, waste. The actual process time is less than 20 days while the whole process, or the lead time, takes over 200 days. Just imagine the value of all that (intermediate) stored product; or, as you could put it, money not paid by the customer. Some of the more recognizable findings were:

  • a third of the waiting was caused by waiting on documentation, somewhere, before QA release
  • the testing and release of some starting materials took as much as two months
  • the QC/QA release process is the #1 priority

And yes, of course, there were many other opportunities for improvement: the process planning; transportation to and from the warehouse; decreasing waiting time of the drug substance, and change over time at packing (the list goes on).


The only step left is to actually start improving on all your new improvement projects! If you’re getting the feel of lean you might want to read about the DMAIC-methodology (define-measure-analyse-improve-control). This methodology will help you and your team to be data-driven, focused on bottlenecks and result-driven.

Blog by: Marc Stegeman - Principal Consultant & Certified Black Belt at Xendo

Click to enlarge example value stream map.




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