The Delusion about Value Stream Map

Leading India’s first total lean enterprise transformation back in the early 1990’s we often huddled on the shop floor to discuss layout changes to improve flow and pace production while answering variable demand (pull). We had no coach teaching us then nor were there seminars or tool trainers. Sometimes I wonder whether we were lucky not to have had partially equipped content coaches trying to teach us random tool usage. When faced with problems of flow, shortages, inventory pileups, imbalance, etc. using a chalk the workmen who were closest to work at tactical level drew layouts sitting on the shop floor portraying how the machines, assembly lines and material flow paths should be organised so that it would result in the best possible flow without any unwanted happening (inventory pileup, backtracking, repetition, rework, imbalance, unwanted communication etc).

Each and every time we did this we ended up drawing the new layout that was a solution to the problems we faced, we were drawing what people today call the future state map! A Value Stream Map only points to symptoms; and to us the symptoms or current state lay right there in front of us, and we were imagining how the future should be, visualizing that ideal state. A current state map would not tell us anything that we did not already know. The real purpose of drawing an Information and Material Flow Diagram or Value Stream Map is to envision the future, like setting the goal! And envisioning better states when needed. At Toyota they do little of such maps, they work directly on the shop floor. Mike Rother and John Shook coined the VSM phrase in the late 1990’s and call it ‘Learning To See’.

I have been through so many factories, seen value stream maps and Kaizen boards plastered all over like wall decorations, yet the factories are not lean. There are a few pertinent points:

1)   Value stream map (VSM) is really not where you begin the lean transformational journey.

2)   Value stream map will not make your company lean.

3)   It is about how you perceive to use the information and material flow diagram or the VSM.

The purpose of value stream map is to design a strategic improvement plan that will be executed over a period of time; it’s not designed to address problems at a detailed level. Value stream mapping has to be a strategic leadership activity that is part of a macro PDSA (Plan-Do-Study-Act) cycle. Designing and making specific improvements requires a series of micro PDSA cycles with involvement from the front line workers. You want those closest to the work designing tactical-level improvements rather than leaders who are too far from the work to determine exactly what should be done to reach a target condition.

A lean journey begins by understanding ‘value’ (lean’s first principal) and then develop a strategy to deliver that value in the most efficient way. Remember lean is strategy work. Understanding the customer demand in terms of cost, quality, delivery logistics, lead times, demand rate and fluctuation bandwidth, sale rates, prevalent gaps, customer satisfaction levels, product strategy, generic strategy if used, competitive forces and competitors, SWOT, core competences, portfolios analysis etc. Most companies work on the push system where variations are internally produced usually from weak marketing systems that are visible in frequent plan changes or schedule interruptions. So excess inventory and wastages of various kinds are only to be expected. Therefore knowing that a company is engaged in the push system is in itself actionable information.

When a company wants to travel the lean journey, they are either guided through programs or by their own understanding take to drawing the VSM and use Kaizen to make improvements. The trap they usually get into is dealing with a segment of the value stream and not visualizing it in entirety and many make the mistake of thinking that lean is just for the shop floor. The common behavior is to feel compelled to start improving the value stream at the micro level and focus on reducing process time. But what happens when you maintain a macro or value stream perspective is the process time reductions become a byproduct of addressing the systems and barriers to flow at a macro level. The key is to direct the team to help them stay focused on the big picture and eliminate the easy-to-see wastes within the value stream. Going into the process-level analysis comes later as you execute the transformation plan and define and document standard work via smaller PDSA cycles. 

“Many good companies have respect for individuals, and practice Kaizen and other TPS (Toyota Production System) tools. But what is important is having all of the elements together as a system. It must be practiced every day in a very consistent manner–not in spurts but in a concrete way on the shop floor.”  – Fujio Cho, President, Toyota Motor Corporation. A value stream map coupled with Kaizen may give localized solutions to individual processes but may not develop into a continuous improvement effort reflecting in the productivity of the value stream or make an impact on the P & L. Companies in the push system work on schedules and not on responding to variable demand. Push systems are not synchronised, hence it cannot pace production; that’s why they are ridden with wastes and poor performance.

VSM is merely one tool in the TPS JIT basket of over ninety tools and techniques and is not a popping pill to become lean, to become lean one needs to develop the daily habits and routines (Kata) of everyone working from top management to workers, and develop the habit of using the philosophy, principles, necessary tools  and techniques to keep improving continuously. Continuous improvement is a mindset and a culture that is always looking for opportunities to do the job better, even when the organization is performing at the highest level it ever has. Continuous improvement is not about the things you do well — that’s work. Continuous improvement is about removing the things that get in the way of your work – the blockades, headaches and things that slow you down.

Remember amateurs work until they get it right. Professionals work until they can’t get it wrong. Lean thinking leads one towards that ideal state or attainment of near perfection, VSM may short stop you by being content with localized or segmented process improvement. Sometimes OEM majors assign consultants the job of teaching VSM and flow to their suppliers in expectation of receiving parts or assemblies on time. Among the reasons why they experience failures in supply is because they set up three to four suppliers for each part or assembly and use threat to control them threatening to stop their supplies because of the options they hold in case the vendor does not comply to the demands made by the OEM. So what also happens is, the vendor who is committed to a spectrum of customers at times has other similar pressures or might just choose to do the better paying job knowing the OEM has other options thereby not complying to supply requirements. These programs usually focus more on material and not on information. It is not surprising to see the OEM send three forms of communication to the vendor on the same day giving different quantity requirements! The last communication could come after half the working day is over! This is such a contrast to the lean principles and processes of lean purchase, and yet they believe and expect the vendor to become lean learning VSM and flow when the OEM themselves are not! So, don’t be under the delusion that VSM will make your company lean.

Sanjeev Baitmangalkar / Stratmann Consulting /