Applying Lean Thinking to Supply Chain Engineering

Since what we in supply chain management and supply chain engineering do is develop solutions to meet the needs of our employers, clients, and their industries, it only makes sense to build our approach on established lean operations principles. Lean thinking should be foundational to the tools and approaches we use and develop.  In particular, we need to pay constant attention to the five Lean Principals.

The 5 Lean Principles:

• Define value from the customer’s perspective.
• Identify the Value Stream
• Make Value Flow
• Pull from the Customer Back
• Strive for Perfection

Let’s take a moment and look at each of these from the perspective of the Supply Chain Engineer

Define value

According to James P. Womack and Daniel T. Jones, authors of the book Lean Thinking: Banish Waste and Create Wealth in Your Corporation, understanding value is the critical starting point for lean thinking. But what that value is is not set by us, or by our bosses, or the Executive Committee.  Value is set by the end customer, and only the end customer. Put slightly differently, value is the specific goods and/or services that meets a specific customer need at a specific time and for which the customer is willing to pay. Anything that does not fit into that description, is not value. In lean parlance it is muda – waste!

According to the authors: “Lean thinking therefore must start with a conscious attempt to precisely define value in terms of specific products (or services or other solutions) with specific capabilities offered at specific prices through a dialogue with specific customers. The way to do this is to ignore existing assets and technologies and to rethink firms on a product-line basis with strong, dedicated product teams.”

But value is a constantly evolving concept. Often, the solution for today’s issue changes into tomorrow’s pain point.  Over the years, we have seen several examples of this.  Consider the need of the local business units within a large corporation.  The procurement of their goods and services were at one time the exclusive domain of Corporate Purchasing.  But this meant that the unique requirements of the individual business unit were often overlooked in the name of greater order consolidation and cost reduction.  And then came along the “center-led” procurement organization.  In this model, the local unit would purchase most items through a company-wide purchasing agreement negotiated by Corporate Procurement.  But when certain unique requirements arose or when significant cost savings could be demonstrated, the local purchasing department would arrange blanket orders or local contracts with their vendor of choice.

Now, all in all, this is really a pretty good model.  But like most exception-based practices, the exceptions gradually become the rule. So, over time, you end up with buying agreements from multiple locations resulting in multiple vendor records for the same item being stored in the corporation’s ERP systems. Consequently, employees might not know which vendor is the one that they should use for a given order. In the end, the Center-led approach has, in many instances, led to confusion and waste. And so, in these cases at least, a new value proposition has evolved. Each company will identify and prioritize the elements differently, but generally these companies now need to simplify the ordering process and related master data management while meeting the unique procurement needs of the local business unit and simultaneously minimizing the overall procurement cost to the enterprise.

Lean Thinking requires the supply chain manager and the supply chain engineer discover what their customers believe satisfies their specific needs at a specific time. But they must also recognize that this is a continuous improvement process, and not a “once-and-done” approach since problems and requirements change over time.

Identify the Value Stream

The value stream can be defined as the various activities that are required for the three critical business processes we must go through to deliver a solution to our customers, either internal or external.

These three processes are:

• The problem-solving task.  This includes the design, engineering and production of our solution.
• The information management task. The process of receiving demand, scheduling and planning delivery of the solution.
• The transformation task. Creating and delivering the solution to our customer.

But it is when we look at all three of these together as a system that we define the value stream.  Since this stream crosses departmental (and often company) boundaries, it necessarily requires cross-functional collaboration of stakeholders from all the affected areas. And this is where we almost inevitably find huge amounts of waste or muda.

Muda comes in two forms. Type 1 muda is the action that adds no value in itself, but is unavoidable, such as the physical inspection of items upon receipt at the loading dock. Type 2 muda adds no value and can be avoided without damage, such as a poorly laid out stockroom that requires considerable backtracking and wasted time in filling orders.

Back to our center-led procurement example, if we had identified all the stakeholders, Corporate Procurement, local purchasing, the end-users of the items ordered, the suppliers, both corporate and local, and together we had mapped the entire value stream, looking for problems and waste, would we have eliminated the issues we discussed.  Probably not. Exception-based solutions almost always devolve. But those companies that did take this more holistic approach tend to have more robust and durable center-led organizations

Make Value Flow

So now we have removed all the avoidable (Type 2) muda in the value stream. And now there is another, totally counter-intuitive task before us. We must make the value-added steps work together continuously (no waiting, stopping, or rework). That sound simple, but that’s not really the way our brains are wired.  It seems to us that doing things in batches will be most efficient.  Paint all the blue things, then all the white ones, followed by all the green ones.  But this results in a series of “batch and wait” steps. We are, in effect, creating our own bullwhip effect within our organizations.

Let’s go back in time to the early 20^th century and stop by the River Rouge Plant of the Ford Motor Company.  Here we see a very early example of flow processing versus the traditional batch process.  Ford didn’t make all the doors, then all the fenders then assemble them to make all the chassis. Instead, he set up conveyors that continuously moved the cars down the line – a flow – and each car “grew’ in an exact and repeatable process starting with a bare frame and ending with a complete automobile at the other end.  And it was this flow process that allowed Ford to assemble over 2 million Model T’s around the world.

 The same approach should be taken in Supply Chain Engineering. There are several aspects to consider:

• Eliminate specialized departments.

• Focus on the end-solution itself and what is required to complete a single solution.
• Ignore boundaries between companies, departments, and individual roles with the goal of “removing all impediments to the continuous flow of the specific solution.”
• Redesign processes so operation of the solution can flow continuously.

Pull from the Customer Back

Another feature of lean thinking is the concept of “pull”.  The goal is to deliver only what your clients or customers want and when they want it (Pull).  A common flaw in system design is guessing when and what the customers might want and pushing products out. But within supply chain management in particular, we see where this aspect of lean thinking can result in rigidity and a lack of resilience.

Kanban is an excellent example.  A Kanban system, whether single bin or dual, provides a just in time supply of inventory with the minimum of excess overhead. But the cost of that is a certain inflexibility.  If, for example, there is a sudden variation in either supply or demand, you may find yourself without sufficient inventory. And if there is any significant disruption to the supply chain, you have no buffer to mitigate the situation. For that reason, it is prudent to maintain a certain centralized safety stock of critical items.  But at the customer end, pull still remains the key.  For example: “No one upstream should produce a good or service until the customer downstream asks for it.” It is these real-time signals that indicate to upstream activities when more is needed.

Strive for Perfection

And finally, the improvement of processes never ends. You must always strive to design, develop, make, and deliver a better solution while improving efficiency. Think once more about our center-led scenario. In the cases where this has degenerated into confusion and disarray, was a continuous improvement mindset used? Most likely not, for if it had, the problems would have been identified and addressed long ago.

To continuously improve:

• “Form a vision, select the two or three most important steps to get you there, and defer the other steps until later.”
• Don’t settle for just being better than your competitors or even your current business practices; if you’re not moving forward, you’re moving backward.  You can’t stand still.
• Observe your outcomes. Analyze the results. And constantly look across the entire value stream to discover new opportunities for improvement.

Lean thinking can make your make your organization’s supply chain more effective, more efficient and more nimble.  And it can make you a better supply chain engineer.