What is Flow Production?

Do you know what Flow Production is? This type of production gained ground in the 1920s and has been used to streamline production ever since. In this blog post, we’ll explain what Flow Production is, why it’s important, and how it can help businesses increase their overall output.

Flow Production is not about setting a Takt time to set goals – that comes later when we move to Pull systems. What Flow Production is, is the movement of Information/ Operators and Materials without Hinderance. Where we find that Flow stops is where we need to focus our attention.

Before we continue, it’s important to point out that while I talk from an engineering point of view, Lean and Flow itself can be translated into any industry – Fast food, Medical, Military, Civil and even hair dressers. So, I invite anyone to read this post as you may be able to incorporate the methods in whatever industry or job you do.

What are the benefits of Flow?

I’ll let you watch this short YouTube clip to see for yourself what the benefits are:

As you can see, doing one piece at a time allows for one finished item to be done without having to wait for the entire batch to be ready, in many cases we would add Queue time to the cycle time for batches which increases the process time. Since there is no queue the item once completed is free to move on to the next stage.

But that’s just one station, this video shows you how a flow production line will work using flow.

What have I used to increase Flow?

Apart from reading many books (guess that’s obvious), I take the simple path of implementing the following structure (Adapted from the work done by Katie Mackle)

Create flow

• Study the process
  • Rearrange the processes making a part into the correct order
• 3S process and area (Sort, Sweep, Shine)
  • Look at each process and remove the simple to find wastes
• Create a Value stream map (VSM) to look at the production line in a heuristic view to look for opportunities
  • ID factors take hinder flow
    • Theory of Constraints (TOC)
    • Total productive maintenance (TPM)
    • Single Minute Exchange of Die (SMED)
  • Use the ID factors to improve flow

Maintain flow

• Understand Complexity of parts and system
• Understand Variation of parts and system
• Understand Mistakes within the processes
• Work to eliminate or reduce these

Organise flow

• Visual management
• Standard operating procedures
• Monitor processes
• Implement Continuous improvements (CI)

Why this order?

This order is important since nothing else matters unless you ‘create’ flow to start with, if the material doesn’t move and you don’t have capacity within the stages, why would you be wasting time writing those SOP’s?

Create flow

We all know that the supply chain is a core part of any business, without parts/raw materials coming into your production line, nothing happens. So start off by looking into how materials arrive to your production line and start the process of removing wastes, later use the VSM starting at the shopfloor level and moving up to factory level (this level shows factory’s as process steps) to see how material moves to and from your company and suppliers to find improvements.

Maintain flow

You can guess what I will cover here, but simply put having a skill matrix and a workforce that is confident in moving to any stage to work will safe guard most situations, but more importantly we want the workforce to follow the flow of work and not wait for it to come to them. This ensures that the most expensive resource a company has is optimised as much as possible even if machines and workstations are left idle for the short term.

Also thinking about the current process & parts, we need to look at the complexity of  both and how we can reduce these, many companies can have too many variations of products which creates the complexity or the build process is extremely challenging and technical to perform, this leads to the likeliness of mistakes being made. Video the process, review the products and individual parts to see what can be reduced or eliminated.

Elon (sorry) said in his recent interview with Tim Dodd, that the best method was to remove everything until you find that the design doesn’t work without a particular item, that’s the one you keep, or redesign 5 items into 1.

Organise flow

This means capturing all the information the department uses on a daily basis to perform its role, then access the criticality of that information, do you need all that to run with? Or can you dig in and throw most of it away to leave you with the core information. That core is the information you need as a bare minimum to operate with.

Think about information as an area of weakness, which in my experience all the knowledge within the department was being held in the minds of two people and working with them, we created the SOP’s. This starts to remove the need to find information, along with visual management you can structure any area to have all the information it needs to run 80% of production and as always manage the 20% strangers that come along.

My thoughts on Flow production

Within the steps above I use the following tools to help me, again remember that every process/company and tools aren’t always compatible, so try another if they don’t work.

Create flow (Think about the Material) =

Availability (OEE) + Heijunka + Line Balancing + 7 Wastes + Capacity + Throughput + VSM + Buffers + TOC + Kanban + Yield & Volatility of supply + TPM + SMED + ADDON

Maintain flow (Think about the Machine) =    

Performance (OEE) + Variation\Complexity reduction + Machine part matrix + Poka-yoke

Organise for flow (Think about the People) =

Quality (OEE) + SOP + Visual Man + 7QC + 5S + Layout

The last step is one of the most important in my opinion which is to implement a culture of continuous improvement, this isn’t always easy but I have found that if I explain to operator what I’m doing and the benefits, they are more forth coming with the issues they see, as I’ve mentioned before feedback is critical for a working relationship and to promote learning with understanding.

Don’t forget, Lean is an educational tool, by teaching people how to see the wastes, they can generate the ideas for you to look into. I run a weekly CI hour with the production team and they are great with pointing out what isn’t and does work, while also giving me feedback of previous changes.

It might seem strange that I suggest doing the VSM after looking at the system (as the Womack and Jones model suggests), but you can’t really create a meaningful VSM without doing the investigations up front and while doing those investigations you can also get in those simple quick wins which in the long run starts achieving the buy-ins from the operators.

The difficulties I have face when implementing flow production, how I overcame them

It’s no surprise that the biggest challenge I have faced as a Production Engineer is the culture and people (that’s why Production Engineer’s become good people managers later on – in my opinion), I’ve had to study and learn how to deal with conflicts and negotiate my way through them. People will always see things from their own perspective and not the heuristic view of the system (that’s why they tend to self-optimise their own workspace).

Getting the systems into place is the next problem as the tools and methods shown in the books and videos are in their ideal conditions, my job has been to create those conditions, or to adapt the tools into an idea of how it can work within the company I’m working for as they all have their own unique way of doing business (again based on someone’s interpretation of an idea).

Another issue with one piece flow is timing, having a constraint in the system can upset the flow and depending on where it is in the production line will have an impact on how severe it affects the flow, you tend to have the constraint upstream i.e. at the start and then all other processes are faster. The theory of constraints deals with this as does line balancing – use these tools to help you.

Don’t forget timing of parts coming into your system like from suppliers is also critical, hence why waste is the top priority in Lean to drive out, with the end goal being the implementation of one piece flow, auto manufacturers have been known to have suppliers on site delivering straight into the production line – here you want to use VSM and work with your suppliers to hold stock or in my case help them with their on Lean initiatives to eliminate their wastes.

That also brings up the inventory, again one piece flow requires Just in Time deliveries, you can’t hold the stock levels needed to ensure production doesn’t stop. So, the whole supply chain needs to support the flow, this is a big task depending on what you produce, how many and the resources you have to implement changes with.

Conclusion on Flow Production

There’s a quote from the ‘Lean Toolbox’ that resonates with me and I always bear in mind whenever I’m looking for improvements to be had.

“If you focus on Flow and Lead time, you drive out waste” – The Lean Toolbox

By maximising flow or by removing everything that hinders the 3 flows discussed above, we can work on reducing lead time by improving processes or redesigning them, this really is the only formula you need as an engineer to start improving with.

My own experience with flow – from Stannah……

Stannah had one of the best flow systems that I’ve seen (and I’ve been to Siemen, Rangemaster, Wilson tools, Yamazaki Mazak and several others), what puts their flow system ahead is the level of organisation and availability on the production lines.

Everything they need is within arm’s reach, Computers tell them what to build next at the start of the line and there’s a PC and testing at the end (this is the same on each line), there are overhead air tools that operators reach for, the work instructions are laid out just above their heads, the parts are fed into gravity racking system so the parts roll forward and are at waist height, the line have a chain driven system that the carriage ride on and it’s these carriages that the product is built on and travels down the line, the line itself is configured so depending on staffing it can be switched from a 3 to 4 to 5 or even 7 stage operation (all line balanced), parts are delivered by material handlers who service designated lines on a schedule. If you want to see flow there’s no better example in my opinion.

Flow Production is a production method that has been used for the last century to help increase production and streamline processes. It can be a powerful tool for businesses to achieve higher output and more efficiently complete production processes. By understanding what Flow Production is, the benefits it offers, and how to implement it, businesses can make sure they get the most out of the method.

Here’s the final visual I wanted to show, you can clearly see that flow enables you to remove the waste of waiting for products to move onto the next stage, either to another process or to a customer, If you could do me one favour next time you’re in McDonalds or a fast food chain, take a closer look at their kitchen as they are one of the best flow line producers! – In approx. 45 secs..

References

As always, I have added Amazon links to these references so you can investigate and get your own copy of their works for you to enjoy and develop yourself with, these links have no cost to you but I will gain a small commission, should you decide to purchase.

• The Lean Toolbox – Bicheno & Holweg
• The Goal – Eliyahu M. Goldratt
• Creating level pull – Art Smalley
• Making materials flow – Rick Harris
• Seeing the Whole – Jones & Womack
• Creating Continuous Pull – Mike Rother & Rick Harris
• TPM – the western way – Peter Willmott
• The Visual Factory – Michel Greif

Just links.

• AW Schultz
• Treston USA
• Thinkflow innovations – Katie Mackle

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