Heijunka and Lean Pitch Chart

Load leveling to create a lean schedule for batch flow, lean pull, or one piece flow

Bookmark = LoadLeveling

What does Heijunka Load Leveling Mean?

One of the primary purposes of value stream mapping is to create flow (ideally one piece flow).

In addition to being a root cause of so many quality problems, (learn more),
batches also cause all kinds of disruptions to continuous flow,
so Load Leveling is an important cornerstone upon which lean flow systems are built.

The idea of lean Load Leveling is to intercept batches of kanban orders or sales orders (or whatever is being processed), and then smooth out the volume of demand (and possibly the mix), by:

1) Releasing only enough orders at a time to meet takt time demand (thereby leveling demand spikes)

2) Spreading the types of orders throughout the shift as much as possible.

Example The batch way to make 10 units of product X, 5 of product O, and 3 of product Z would be: XXXXXXXXXXOOOOOZZZ The Level Load way might be: XXOZXXOXXOZXXOXXOZ

Bookmark = PitchBoard

Lean Pitch Chart

Also known as Pitch Board or Production Pitch Tracking Chart
Used to level the flow of work to an operation set up for lean flow

A Lean Pitch Chart is a visual control method that is used to level the flow of work, and to measure expected vs. actual production output per pitch cycle.

This lean tool is appropriate for operations that:

1. expect a steady flow of production - based on takt time.
   (you would use a Lean Pull Priority Queue for a process governed by lean pull rather than lean flow)
2. produce a single product or product family
   (you would use a Heijunka Load Leveling Box for a process that also needs to consider variety mix)

There are several ways to use your Systems2win Pitch Chart Excel template:

1. If it is convenient for your workers to do data entry directly into the computer,
   and the Pitch Chart will almost always be visibly displayed on a large monitor throughout the day - (so that it meets the criteria for an effective visual control), then you might enter your data directly into the Pitch Chart Excel document.
2. More commonly... you will print the Excel template, and have your workers manually enter the data throughout the day. (Perhaps having a low-pay-scale person enter the data at the end of the day just to cross-check their math)
3. You might personalize the Excel template for creative variations for unique situations.
   Perhaps use it as a prototype to create a non-computer-based Pitch Board using moveable magnets, or an erasable white board, or a wall board with pocket folders, or any other creative way of accomplishing the same objective.

Monthly Pitch Log

The Monthly Pitch Log provides a color-coded summary for at-a-glance trend analysis,
so that your supervisors and managers can quickly see patterns that need attention.
(Does productivity often dip after break times? Are Wednesdays better than Fridays?)

The Lean Pitch Chart and Monthly Pitch Log Excel templates
come with the Kaizen Continuous Improvement bundle of templates.

Bookmark = Heijunka

What is a Heijunka Load Leveling Box?

Also known as a Lean Schedule Box or a Post Office Box
Used to level the flow of both work volume and variety mix

A Heijunka Box is a physical device used to level the flow of work volume and variety mix.
(Contrast this with the Pitch Boardor Priority Board, which level work volume only)

A Heijunka box is usually a mailbox-looking thing mounted on a wall - with cubby holes that each hold one kanban card or folder or other form of work authorization.

The labels at the top of the box are usually time periods (in the time increment determined by the Pitch ).

If there are labels on the side of the box, they will indicate variety mix. More commonly, there are no side labels, and variety mix is determined by the contents of the kanban card or folder in each slot.

If the product family has products with varying takt times, (e.g. some products take 2 mins, some 4 mins, and some 8 mins), then some of the slots will be empty beneath a kanban card for a long-takt-time product. It is common to color-code the folders or kanban cards to make the length of takt time visually obvious.

If there is more than one worker, then either:

1. The workers work as a team
2. Each worker pulls work authorization from the Load Leveling box
3. Each worker has his or her own Heijunka Box

Bookmark = SchedulingTimeIncrements

Heijunka Software

Although some ERP applications do offer electronic heijunka load leveling options, it is far more common (and usually much simpler) to use a physical heijunka box...

unless you only need to level the flow of work (without consideration for variety mix) - and then you can use the Systems2win Lean Pitch Chart template.

Late Load Log

A simple visual system to continuously improve your heijunka scheduling

You can always just glance at the heijunka box itself to see orders that are currently late,
but that just takes care of your immediate fire-fighting - and doesn't provide the visibility of trends needed for more proactive continuous improvement.

That's why it is often worth the extra data entry to also maintain a Late Load Log - comparing estimated to actual completion time - with clearly articulated comments explaining the reasons for each miss.

Bookmark = PullQ

Lean Pull Priority Queue (FIFO Lane)

Also known as Lean Priority Board
Used for load leveling production flow to an operation set up for "pull" (rather than "flow")

One lean principle is "Flow where you can, pull where you can't, only push with a FIFO Lane"

When a shared or constrained resource supplies a supermarket using a pull system kanban system, the visual system for production tracking is usually some form of a Pull Priority Queue.

When Production Kanbans (or similar production signal) return to the producing operation, they are typically put into the Pull Priority Queue in FIFO sequence. (first in first out)

Please keep in mind that every application of lean principles is an invention. Your "pull priority queue" could be a board, rack, track, wire, or a taped off lane leading to the work center with carts carrying the FIFO-sequenced incoming work. Also keep in mind that the FIFO lane might not use FIFO - but could use any sequence-scheduling algorithm - which is why the more correct term is sequenced pull lane.

The imporant thing is to incorporate some form of color coding (usually green, yellow, red) onto the background of your lean Pull Priority Queue to indicate the likelihood that the orders in that portion of the queue will be completed on time.

Color codes for a Lean Pull Priority Queue:

• Green = Plenty of time to fill the orders in this portion of the queue.
• Yellow = Heavy load - but should be able to fill these orders without overtime - as long as nothing goes wrong.
• Red = Will require overtime or the last jobs will be late - unless preventative action is taken.

Pull Priority Queue Hourly Status Report

With one glance at a Pull Priority Queue, you can tell whether that production center is on track to meet its production requirements.

But in order to view trends over time, you will want to maintain a Pull Priority Queue Hourly Status Report.

Every hour (or your chosen time increment), you color-code the cell for the color that you see beneath the last order in the Pull Priority Queue.

Bookmark = JobLog

Job Log

aka Job Tracking Log, or Job Estimate to Actual Tracking

One of foundational principles of any lean management system is that every lean production system needs a corresponding lean management system - and one key element of each lean management system is to provide a way for the workers to record clear and articulate comments explaining the reason for every "miss" of expected vs. actual performance.

For this purpose, the best lean system for visual management for a pull operation is a simple Job Log - that compares estimated to actual set up times and run times per job - with space for the operator to explain the reasons for each miss.

Bookmark = Reading

Suggested Reading and Resources for Lean Flow

If you appreciate our free online training, you can help support us by purchasing your books through these links to Amazon.com

These books introduce even more approaches for Lean Load Leveling -
such as the Card Rack Scheduling Board, a Floating Pitch Board, Refinish Reorder Boards, visual control boards for non-cyclical tasks, and more...

Do something about the problems you find

A primary purpose of any lean visual management system is to reveal problems.

The assumption is that you will actually do something about the problems that get revealed.

• Perhaps your team might maintain a Pareto Chart of the top 3 priority problems you are currently working on - and publish it on your Team Accountability Board.
• Perhaps a team member might volunteer to lead an A3 problem solving exercise.
• Perhaps a problem might prove worthy of a kaizen event.
• Perhaps a problem might need to be escalated to a higher tier of your lean management structure.
• Perhaps a problem might affect and be of interest to the larger value stream.

If your lean leaders don't actually solve problems as they surface - then people will quickly lose interest, and wonder why they're doing all this extra paperwork to identify even more problems that management ignores.

If it is to succeed, every lean production system must be implemented with a corresponding lean management system.