Effective shop floor production planning and execution is a tough gig. While there isn’t a shortage of technology or methods to help shops plan for an ideal production picture — execution is another ballgame entirely.

From failing to account for real-time conditions to expecting a scheduling algorithm to magically solve all of your production problems, here are six common shop floor production scheduling mistakes that can result in late orders, cash flow challenges, and dissatisfied customers.

1 – Not proactively anticipating shop floor variability

“Stuff happens” in manufacturing: materials are delivered late, a key employee gets sick in the middle of a big job, a rush order comes in that puts all other projects on hold.

While you can’t predict what will happen at the outset of a job, your shop does need to proactively anticipate the unpredictable changes that are destined to happen in the middle of an order and adjust accordingly. If you’re not actively acknowledging that “the only constant is change,” especially on a manufacturing shop floor, then even the smallest shift will have a domino effect across many operations and resources, causing significant production delays.

2 – Not having the visibility to effectively deal with variability

One of the reasons variability causes significant delays is because manufacturers don’t have visibility into what is truly important to identify when conditions on the shop floor shift.

This is an unfortunate symptom of having to attempt to execute a “plan” generated with spreadsheets or your ERP or APS system. When conditions change, you’re stuck with reworking your spreadsheets or rerunning your scheduling programs to generate a new plan — a plan that becomes obsolete upon the next change, rinse and repeat.

What you need is real-time visibility of shop floor priorities that dynamically adjust as conditions invariably change throughout the week, day, or by the minute.

3 – Not knowing when to start your jobs

Most manufacturers don’t have visibility into the right time to start their jobs. As production staff don’t want to risk starting late, orders are often planned and started as soon as possible. Unfortunately, this has the undesirable effect of flooding WIP with too many orders, too soon. Much like merging more traffic onto an already crowded highway, this just slows the flow of production and increases wait times and expands total production lead time. Worse, having too many jobs in WIP confuses true priorities, increasing the risk of working on the ‘wrong’ job and introducing more variability into production.

Knowing the right time to start jobs will control the total volume in WIP (without the risk of sending it out to WIP “too late”) and allow work to flow through all of its resources to completion in the most expeditious manner possible.

4 – Not really knowing when you’re going to need materials

Similar to #3, if you don’t have an objective (i.e. correct job start date), you will likely be starting jobs — and planning and purchasing material for said jobs —way too early. We’ve seen situations where material was purchased and received months in advance “just in case” the manufacturer wanted to start a job early. Not having visibility into when you will actually need material means tying up cash flow for work orders that can’t be started for days, weeks, or even months.

5 – Focusing entirely on work order due date

Many DIY shop floor scheduling methods and traditional ERP scheduling software depend on due dates to prioritize work orders. In other words, a job due in three weeks will automatically be given more urgency than a job due in six weeks, regardless of what operations are required to complete or their complexity.

While this approach makes sense on the surface, it doesn’t always prioritize the right jobs: The six-week order may actually be in more danger of being delivered late if it hasn’t been started yet, even though it’s technically due later, especially if it has outsourced operations, multiple subassemblies, etc.

6 – Expecting a scheduling algorithm to solve everything

Many manufacturers turn to shop floor scheduling software to help them manage these problems — and become increasingly frustrated when the problems persist despite the software. Unfortunately, ERP and other scheduling systems simply weren’t designed to fix common shop floor production scheduling mistakes.

To allocate future capacity and create an accurate production schedule, your estimated setup and runtimes also have to be extremely accurate. Once in place, the priorities generated by any traditional scheduling program only remain as accurate as the last time it was run, which means you’re constantly out of sync with shop floor reality.

A better way to manage shop floor production

Manufacturers need to make the shift from thinking about better shop floor scheduling to thinking about promoting better flow of materials and information throughout the shop.

Not only will this shift help avoid these common shop floor production scheduling execution mistakes, but it will also rally your team around priorities they can believe in, reduce lead times, and help you make customer promises that you can keep.