Line Balancing – The Road to Optimal Productivity

  • 10 January 2017
  • Number of views: 6901
Think of the road network as a production line. Before you get into your car to go to work you are the equivalent of raw material. Once in your car and out on the road you have become WIP (work in progress). When you arrive at your place of work your status has changed to FG (finished goods). Once inside, depending on your job, status, mood, etc. you go to the customer adding value or you go to the FG warehouse collecting dust hoping for someone to buy you.

You know your way to work inside out. You know when and where the traffic (WIP) is flowing freely at a good steady speed somewhat above the speed limit and you know when the cars bunch up and slow right down in front of the speed cameras. You know the roundabouts that also slow things down and perhaps some traffic lights (Kanban) that are poorly synchronised bringing everything to a standstill. Of course, there will be the persistently slow moving car in the outside lane and other little hiccups.

But did you know that on your journey into work you could be experiencing what it is like to be WIP on your factory’s production lines?

Look out for the speed camera effect


Just as you know your journey, you are very familiar with your shop floor. So, try to look at it again, but from a different perspective. Do you see the speed camera effect? Do you have WIP piling up in front of certain machines or lines? Does a shift turn up with nothing to do because everything has already been consumed by the previous shift? Do some areas just look busier or quieter than others?

These are just some of the signs that your lines are out of balance or out of synch, or that planning and execution are not aligned. When you see the speed camera effect on your shop floor – whether it is made up of WIP, materials, or operators – you know that your line productivity could be improved.

A stop start journey into work may be the norm and you have to accept that there is little or nothing you can do about it. Your shop floor however is a different matter. You have the power to change it for the better!

Begin at the end

Walk the length of your production line(s) and make a note of what you observe. Start at Goods Out or the FG warehouse. Are things frantic, or dead, or humming along nicely? And what could that tell you? Now go to Pack Off. Can they keep up with what is coming at them or are they idling? Continue your walk further upstream and look at the space between each machine or process. If there is WIP, can you tell how long it has been there, if the quantities are acceptable and what product the WIP relates to? Most production lines have at least one process that is significantly slower than the machines up and down stream of it. For example, baking or curing. What about Goods In and raw material stores? Are they stuffing or starving the production lines? The last stop on your tour is the Planning Department in order to experience the shop floor performance from their perspective.

Collect data and facts
If your FG warehouse is bursting at the seams, you need to understand if you are over producing in general or if you are doing a perfectly legitimate stock build to cover peak or a large order. Always check your immediate impressions and assumptions against data. The data collection starting point is the Sales Department. Knowing what the customer wants is crucial for understanding whether the machines are running at the right speed and whether the shifts are sized correctly.

Now it is time to analyse the production data. What is the capacity of each machine as per the manufacturer’s specification? What speed are you actually running the machines at? What is your ideal Takt time? What is your current line speed? How do shift change overs and breaks, and maintenance affect the line balance?

When you know what you need to do, what you theoretically can do, and what you are actually doing you can start to make adjustments.

Putting the jigsaw puzzle together
You now know your current and forecasted customer demand, you know what your machines, lines, and people are capable of, so now it is time to match the two. Perhaps things are as good as they can get, given the physical and financial constraints you have to work with. If that is the case then carry on. However, what if you categorised your products and set up cells or dedicated lines for certain product profiles? Could you then run your lines, people and materials more effectively and perhaps even take on more? Only when you have considered the big pieces of the jigsaw such as layout, flow, planning, staffing, and maintenance should you go on to the smaller pieces and fine-tune each line (perhaps using line balancing software).

A jigsaw puzzle can be taken apart and put together numerous times. Remember this when market conditions change, when you win or lose customers, or when your customers change their requirements. That’s when it is time to do the line balancing exercise again from the start.

Fig. 1: WBS putting the jigsaw together in a new way based on analysis and data

An independent view
Sometimes, it is helpful to get someone who is not deeply immersed in your organisation to have a look, someone who understands what to look for and who can provide an independent point of view for you to consider.

WBS Group have provided this independent view for many of our clients and gone on to help implement our recommendations.

To find out how WBS can assist you in optimising your lines or other manufacturing processes simply contact us  for an initial FREE no obligation consultation.

You can also read more about the assessments we offer on our website.
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