Help Your Process Flow with Line Balancing

Lisa might use this once she has done her Value Stream Map (2.4) with timings, and wants to see if she can make the experience faster for the customer. Line balancing is where we improve Flow by balancing out the steps in our process, so that they are faster than the rate of customer demand, or Takt time.  This can mean combining steps where possible to eliminate queues or wait time, or splitting steps into smaller parts so they can be performed more quickly than our customer demands.  A Line Balancing Chart helps us visualise it so we can see where we can improve.

As usual, a picture is worth a thousand words – let’s look at the process steps we started with in our SIPOC (2.3):

Figure 16: Example of our initial line balancing chart, where each process step is being performed at the same time as they move along a “production line” that is always full.

In the example above we have a service that needs to be produced once every 12 minutes to meet customer demand.  In other words, 12 minutes is our Takt time.

To create this service, we have five process steps.  Our timings look like this in minutes:  7, 3, 1, 3, 14.  Every step is always working, as items constantly move through the creation process.

Our two longest processes are 7 minutes and 14 minutes each.  We also have a problem, because if one step is taking 14 minutes and we need one every 12 minutes, we won’t meet our customer demand.

So how do we balance this workflow?

We can see that the second longest process (step one, “Call”) is 7 minutes.  Steps two and three after it, however, only add up to four minutes (3 + 1).  So we have the opportunity to combine the first three steps to reduce the number of total steps, with the added benefit of eliminating queues or wait time in between.

Step 5, however, is 14 minutes – 2 minutes over our Takt time.  We can split this step into two, or add some of it to another step in order to bring it under 12 minutes.

Doing this and balancing out our process steps, we have a much more streamlined process with less wait time, fewer handoffs and that we know meets customer demand.

Figure 17: Example of our process after performing line balancing – some steps are combined, reducing queues in between, and one step is split up, ensuring our longest process is still under Takt time.

Using a Line Balancing Chart to Start Initiatives

Using a Line Balancing chart to start an improvement initiative is easy – we just need to reveal the right things.

Remember, when timing a process we do so a minimum of ten times and use the lowest repeating time (2.5).  However, we can also draw in the maximum time for each step.  This will show us the lowest repeatable time versus the maximum time, with the time between them revealing any variations in time when performing the process.  And what causes these variations?  You guessed it – waste (3.1) and not having or following a standard process (5.4).  This variation can be a good opportunity to focus a Lean initiative on.

This is why problems are such great opportunities.  Once the process is improved, we can create a new standard process based on the changes, and then improve it again.

Figure 18: An example of a Line Balancing chart showing variation in times when performing a process.  This variation is the perfect opportunity for a Lean improvement initiative.  

We could potentially reduce this variation and the time of any remaining steps as well.  Getting rid of NVA steps or processes (2.5), getting rid of the Eight Wastes (3.1), using quick changeover techniques (3.5) or adding error proofing and Autonomation (4.2), using 5S to organise work-stations and keep items close at hand (4.4) can all help reduce and balance out our remaining total Lead time even further.

Selected chapters from the story within Five minute Lean:

• Lean Parable – Where Lisa Makes a Change
• Lean Parable – Where Lisa Discovers a New Way
• Lean Parable – Where Lisa Performs a Balancing Act
• Lean Parable – Where Lisa Pulls the Trigger
• Lean Parable – Where Lisa Sets a New Standard
• Lean Parable – Where Lisa Becomes a Leader

Check out these selected chapters from the teachings within Five Minute Lean:

• Five Minute Lean – Use Feedback to Fix and Guarantee
• Five Minute Lean – Eliminate the Eight Wastes to Improve Flow
• Five Minute Lean – Work Towards One-Piece-Flow (and Reducing Silos or Batching)
• Five Minute Lean – Present and Manage Your Change Using an A3 and LCA
• Five Minute Lean – Make Feedback Meaningful with Kano Analysis
• Five Minute Lean – Add Important Data to Your Map
• Five Minute Lean – Go to the Gemba
• Five Minute Lean – Create a Pull System with FIFO, Kanban Triggers and Visual Management
• Five Minute Lean – Use Pareto to Find Where to Start
• Five Minute Lean – Gather Direct Feedback and Indirect Feedback
• Five Minute Lean – Heijunka: Level the Workload when Demand Fluctuates
• Five Minute Lean – Create a Future State Value Stream Map
• Five Minute Lean – Use Kaizen and Kaizen Events to Help Stakeholder Buy-In
• Five Minute Lean – Introduction
• Five Minute Lean – Get Your Map Started with a SIPOC
• Five Minute Lean – Help Your Process Flow with Line Balancing
• The Five Minute Catch-up
• Five Minute Lean – Collect and Measure Feedback With the Net Promoter Score
• Five Minute Lean – Map the Value Stream to Reveal Opportunities
• Five Minute Lean – Put it Together With Design for Ease of Use