Our Sites

Streamlined scheduling suits fabricator

Estes Design and Manufacturing implements software for efficient scheduling, work flow

Panel bending workcell

Estes has invested in a bank of automated laser cutting , folding, and bending centers, including this panel bending workcell from Salvagnini.

Ryan Estes sees the value of a paperless shop: no job packets, no drawings, clear revision control with the latest and greatest for each job in one place on a server. Eventually he'd like to log on to a computer and see exactly where each job stands, what each requires, the personnel assigned, when each job will be scheduled and completed, the drawings and design data, and quality control information—with just a few clicks.

Indianapolis-based Estes Design and Manufacturing is almost there. In recent years the company has made significant strides in adopting manufacturing- friendly information technology, marrying enterprise resource planning (ERP) and scheduling software to ensure work flows efficiently through the shop.

Ryan Estes, marketing manager and nephew of the company founder, said the job shop made significant investments over the past dozen years in fabrication technology—Salvagnini auto- mated panel benders with robotic loading and unloading, a Salvagnini laser cutting system and automated punching cells, an Amada robotic press brake, the works. Recently the company has attempted to tie together the work flowing through those machines with ERP and scheduling software, rooted in manufacturing's theory of constraints (the floor can produce only a finite amount), to take full advantage of the high-tech equipment on the floor.

An automated laser cell doesn't mean much if it just forces a bottleneck downstream. According to Estes, knowing what job will hit where, and when, helps the job shop take full advantage of equipment and people. In other words, a shop may have the best people and equipment in the world, but if they don't work together, neither has much value.

About Algorithms

Key to scheduling, said Estes, is the backward finite algorithm, a bit of software-embedded math that calculates when jobs should land on the shop floor so they will be completed on time. It's "backward" because the algorithm schedules by starting at the due date and moving backward; and it's "finite" because the shop floor has a defined, finite capacity.

Put another way, "the 'finite' defines the capacity limitations," Estes explained. "We're limited by people and machine time. An 'infinite' algorithm would state, 'Here are the jobs you have, and you have all the time in the world to run them.' We obviously don't have that."

This backward finite algorithm is embedded in the shop's Visiprise Shop Floor Scheduler, which, together with the company's Made2Manage ERP system, helps automate work flow planning. The ERP software shows the what—what material, what part, what client, what order number—and the when—the job due date. Meanwhile the scheduler determines upfront if that due date is possible, identifying bottlenecks and delays before they happen.

How It Works

Once the shop wins a bid for work, "we'll create a job in Made2Manage to meet that demand," Estes said. "On it we'll put the part number, due date, quantity, and the routed work centers and machines required to fabricate it. Once a day or more, the information is exported to Visiprise. In that software, we've set up all of our machine [capabilities], and we've defined each machine's capacity per shift. We tell it to run the schedule, and it does all the number crunching, using the job data and fitting it within the capacity of restraints we've given it. It will give us a scheduled start date for each operation within that job, and it will tell us which of those jobs are projected to be late."

The shop also can run what-if scenarios, particularly if quoting large jobs. This helps both the company and customer: If the shop doesn't have nearly enough capacity to complete the work by the due date, the company will look for alternatives to meet customer needs; if it's borderline, Estes said the shop can quote the job, run a what-if analysis through scheduling software—considering other jobs in the queue—and give a potential due date that may be slightly farther out than the request for quote dictates. The shop may or may not win the work, of course, but if Estes significantly beats a competitor's price, the slightly longer lead-time may not be a factor.

"If we see a block of jobs will be late due to a machine bottleneck [or other issue]," Estes continued, "we can work overtime, add people, or divert those jobs to different machines." He emphasized the main benefit: Managers address the problems upfront, before they ever hit the shop floor, avoiding 11th-hour surprises.

Manufacturing scheduling systems

An employee at Estes Design and Manufacturing enters job data into the company's enterprise resource planning and scheduling systems.

Once jobs are assigned a start date, the job data is exported back into the ERP system. From here floor managers and operators use a software module that serves as a kind of "window" into the company's ERP. At touchscreen terminals throughout the plant, operators see what jobs are in the queue for a particular machine, and they also can see where jobs stand upstream. For each job, the system gives all the pertinent information, including material, quantity, and job number. The operator runs the job, records the quantity, the labor, as well as the scrap using a touchscreen interface, which transfers information directly back to the ERP platform.

At supervisor terminals, touchscreens have an embedded Master View module that lets managers review all orders, giving a macroperspective to operations. "You can drill down into each to see the bill of materials for each component and where each of those components are," Estes explained.

This comprehensive production "dashboard" allows managers to look on the horizon and avoid things like unneeded overtime. Consider a project due Monday is, for whatever reason, behind, so over the weekend managers plan for overtime at the laser cutting and bending center, so work can be completed in time to reach the welding area Monday morning. But what if an outsourced component is late? The welder would arrive Monday and find every part he needs—save one—meaning not only will the part be late, but the shop also paid workers overtime. Production dashboards, Estes said, help managers avoid this conundrum.

Another benefit: Such software gives an easily retrievable record of shop capacity, machine uptime, and bottlenecks. That historical database, Estes said, helps the company periodically re-evaluate its manufacturing process and pinpoint potential equipment purchases for areas that would benefit from increased capacity. "The software helps us identify where the chronic backlogs are," he said, "so it will give us guidance for our acquisition needs."

Unfinished Business

Estes conceded the company has a long way to go for an ideal work flow, adding that the shop hopes to add other components to further automate work flow down the road and, ultimately, eliminate paper on the shop floor. On the horizon, managers hope to integrate quality control data as well as part drawings. The goal: Anything and everything about a job should be at the operator's fingertips.

While Estes' software can account for the capacity and limitations of different machines, it has yet to do the same for people. Estes must manually assign work to personnel. Software has the potential to automate this, just as it does with machinery, but there's a problem, Estes explained. Unlike production environments, Estes' shop floor employs multitasking workers, and one person isn't necessarily tied to one machine or even a group of machines. Instead, a welder may spend part of his day gas metal arc welding an assembly, then performing some precision gas tungsten arc welding, and then finally spend time in the finishing area. A laser cutting operator may move to the bending area to clear a bottleneck.

Multitasking can make a job shop really hum, but it can add challenges to software attempting to automate personnel scheduling, Estes said. He added that, though automated personnel scheduling has had significant success in production environments, such software would be charting new territory for Estes. Currently the job shop is working toward a goal where software could develop schedules for workers based on, again, that backward finite algorithm hinging on job due dates.

Such functionality, he added, "would be incredible."

Estes Design and Manufacturing launched more than 30 years ago as a design and engineering company. Over the years it has shifted focus to the shop floor, evolving into a 96-employee company offering contract manufacturing along with value-added design and engineering. Company founders, with roots in design and experience on the shop floor, have strived for that seamless flow from design through manufacturing and inspection. In the coming years, Estes said, the company hopes to utilize software technology further to make that seamless flow a reality.

Estes design shop floor

Knowing what job will hit where, and when, on the shop floor helps Estes Design and Manufacturing take full advantage of equipment and people.

About the Author
The Fabricator

Tim Heston

Senior Editor

2135 Point Blvd

Elgin, IL 60123

815-381-1314

Tim Heston, The Fabricator's senior editor, has covered the metal fabrication industry since 1998, starting his career at the American Welding Society's Welding Journal. Since then he has covered the full range of metal fabrication processes, from stamping, bending, and cutting to grinding and polishing. He joined The Fabricator's staff in October 2007.