Scheduling. It just might be the holy grail of manufacturing. Its power is legendary. Mysterious groups are rumored to possess it.
Like King Arthur, manufacturing company leaders assemble teams and send them on quests in search of it. These Knights of Manufacturing seek an object, a software application that, once possessed, will grant the company ultimate power. The problem isn’t that those who seek scheduling aren’t worthy. As with the legend, the problem is that, those who seek scheduling spend considerable time and resources searching for something that is poorly defined, often misleading and may not even exist.
In manufacturing, scheduling is the assignment of all the processes, resources and capacities related to fabricating a part. It is typically referred to as either “backward” or “forward” in nature. Backward Scheduling works from the due date of a part to determine the start date of the fabrication process. Forward Scheduling works from the date resources needed to fabricate the part become available in order to determine a delivery date. Scheduling software uses computer algorithms to optimize the required process so that resources are used at the most effective time, based on the company’s backward or forward process.
If you ask two different people at the same manufacturing company whether they schedule backward or forward you will likely get two different answers, neither of which is accurate. Most companies really do “schedule” backward and forward, at the same time. They use a “forward scheduling” model on the commercial side of the business where a quote is generated, by applying a time and cost formula to the part. This usually involves counting the number of holes and bends, adding an allowance for scrapped parts, estimating the labor and material to be consumed and estimating the machine cutting time. Then, on the manufacturing side, the company uses a “backward scheduling” model in order to be lean and meet the promised delivery date. This makes the quest for scheduling a little more Monty Python than King Arthur and creates a multi-billion dollar software industry in the process.
The company seeks only a software application that will help them deliver on time; one that will put the fires out and end the confusion between sales and production. They see no reason why scheduling software won’t solve their problem especially if it can be linked into their quoting package, print nice routers and work with bar codes. And so, in love with the power the grail will bring them, another quest begins for scheduling software without even knowing what it looks like.
The seekers soon find scheduling software everywhere and it all looks the same. Which one is the true grail? Legend says it has a backward-finite scheduling algorithm; but, what about Capacity Planning? Some claim to have Advanced Planning and Scheduling (APS) in order to optimize the required materials and capacity needed while scheduling production against resources simultaneously. There are Finite Capacity Scheduling algorithms, which allocate resources over time with capacity that is set. And, there are Infinite Capacity Scheduling algorithms, which outline operations without regard for capacity or resource loads. Then, there is Order-based scheduling (OBS), which prioritizes parts by a shop’s set work-in-progress (WIP) criteria. Rumor has it that the one that can run “what-if” scenarios is the true grail and it creates a Master Production Schedule (MPS).
What if the grail doesn’t exist? “Scheduling” by definition is not an object that one can attain. It is not a noun; it’s a verb. Companies take on this quest for scheduling every day and just when they think they have it in their possession, they discover too late that the grail has eluded them. Maybe there is no grail at all, only the idea of a perfectly scheduled shop. Companies, like King Arthur’s Camelot, could spend their entire existence in search of this ideal only to fall apart. Why? Because, let’s be honest, in the real world, a customer with an order determines the schedule.
So, rather than spending time on a legendary quest for a potentially unobtainable ideal, why not use real data, such as actual costs for labor and materials to make real quotes? Why not make production decisions based on real deadlines, real work in process, actual costs, exact lead times, and real inventory? Wouldn’t knowing the real aspects of your manufacturing process be more powerful than chasing an ideal? Wouldn’t software that reports critical data, in real-time be a better investment? Don’t make schedules -- make informed decisions.
Lantek Sheet Metal Solutions is the world’s largest provider of integrated CAD, CAM, Nesting, ERP and Automation solutions. Lantek is chosen by more customers and machine manufacturers worldwide than any other product to conserve time and material in manufacturing. Founded in 1986, Lantek has more than 11,000 customers in 100 countries worldwide. Lantek’s world headquarters is in Vitoria-Gasteiz Spain and US headquarters is in Mason, OH. Lantek is supported by offices all over the world.
Lantek Systems, Inc.