Rockwell Automation''s Twinsburg, OH plant manufactures programmable logic controllers (PLCs), input/output (IO) cards, communications interfaces and motion controllers. Products are processed through printed circuit board assembly and through an electromechanical assembly process.
In the early 1990s, management at Twinsburg put the plant through a "cultural revolution," instituting cellular manufacturing principles and high-performance teams that brought together all the plant floor players: engineering, plant floor management, and manufacturing associates (who actually build product).
A key element of the transformation was the use of real-time shop floor data. The company implemented a hardware architecture of Allen-Bradley PLCs linked to a VAX computer. Rockwell Software RSBizWare RSSql™ was adopted for automated, real-time data management.
RSSql easily integrated with Allen-Bradley controls in use across the plant floor and smoothed the delivery of data to a central Oracle® database, as well as to machines on the plant floor for customizing products and error-proofing processes.
RSSql helped move the plant away from manual data collection, which inevitably caused gaps in data, especially if the administrator was not on site. When RSSql was adopted, it became possible to acquire more data than ever before, whether the administrator was on site or not. The ample amount of data ensured that every event was captured, rather than just logging the "big picture."
With RSSql, a single engineer was now able to perform analysis of reports in real time. Previously, five or more people used cumbersome electronic spreadsheets to analyze often inconsistent and inaccurate data in reports -- a process that typically took four hours.
RSSql enabled Rockwell Automation to measure cycle time in smaller pieces and analyze it at a finer level. For example, the company cut cycle time from 28 days to 10 days to 5 days. This dramatic reduction significantly improved customer service, increased inventory turns, and lowered operating costs.
The company''s manufacturing resource planning (MRP) system handled production on an on-time-to-promise basis, meaning that customers ordered product and Rockwell Automation promised a delivery date -- which didn''t necessarily fit the customer''s time frame.
"The MRP system doesn''t prioritize orders and assumes infinite material and production capacity," said Mike Reynolds, director, Twinsburg Operations Control & Information Group. "We want to do a better job of meeting the customer''s need."
By early 2001, Twinsburg''s product mix and volumes had shifted. Over 1,700 different products were being built, with volumes ranging from 100-50,000 per year. "Our cellular approach was inhibiting us from reaching the next level of improvements," said Reynolds. "In a cellular layout, there is typically a single product focus in a cell. Processes are optimized for a product family and priorities are easily determined."
As the plant''s product mix grew, so did the mix in the various PCB assembly cells. Ongoing process improvements had diminishing impact on the cells'' performance.
"All the benefits of a cellular approach began to work against us," said Ron Stettler, manager, Manufacturing Execution Systems. "Cells work well if you have a high volume, but a diverse volume introduces too many opportunities for processes to sit idle. Our outdated electronic manufacturing strategy (EMS) didn''t afford a lot of flexibility.
"We kept the electromechanical assembly the same, but given our product mix, we decided to migrate the PCB assembly area from a cellular layout to an undedicated flow layout," Reynolds added.
Various divisions at Rockwell Automation -- MES, plant floor IT, production area supervisors, planners, procurement, order services, plant management -- knew that a flow layout would introduce new complexity, since multiple products would now share a single resource.
"Everyone agreed that we needed a new system that would accommodate our vision of delivering product on an on-time-to-customer-want basis, fit within our larger goal of standardization on the plant floor, and prioritize production to accommodate a greater breadth of products," said Stettler.
"Rather than build a whole new system," added Reynolds, "we wanted to integrate and take advantage of existing IT investments. We couldn''t wait for another ERP panacea."
While changes were being made to the shop floor layout, the Rockwell Automation team realized that, in order to transition from cell to flow layout, they also needed a software package that would facilitate product scheduling in a flow layout.
The Rockwell Automation team considered a variety of advanced planning systems, including Rockwell Software RSBizWare Scheduler ™. "Scheduler enabled us to do everything we wanted to do, but at a much more competitive price than other vendors'' offerings," said Reynolds. "Plus, Rockwell Software offered a smaller footprint, shorter timeline, and more simple implementation."
"Integration with our existing production control system was fairly easy since we can use a central database to share data between applications," added Stettler.
One of Scheduler''s dominating features is its flexibility. Normally, Scheduler gives the best sequence. Rockwell Automation''s application is unique, using Scheduler to perform demand planning to look at material decisions that impact multiple facilities.
"Scheduler is more than just workflow management and production schedules," said Reynolds. "It''s an end-to-end solution that gives a deterministic list of priorities regarding materials, equipment, and personnel with synched processes across plants and shifts."
"We were going from product-focused serpentine lines, in which one line might work seven days per week while another sat idle, to discrete lines in a switch matrix system," Reynolds explained. "With the new setup, we wanted to avoid underutilization of assets."
Before Scheduler was adopted, each department was managed in its own way, with minimal standardization. Scheduler replaced manual decision making and helped meet Rockwell Automation''s larger goal of standardizing the plant floor.
"From upper management to the workers on the shop floor, our people now understand an explicit set of rules instead of assumed rules that encourage working in a vacuum," said Reynolds. "One set of rules and one output helps us know what to start and what to move through the plant."
In addition, Scheduler provides a prioritized components list to the company''s purchasing department to expedite, enabling purchasing to focus on the component that will have the greatest impact on the business.
And to access reports, employees don''t have to go through the company''s inflexible and difficult-to-use MRP system. Scheduler makes it possible to modify reports at will. Information is consolidated, from catalog information, subassembly information, card data, and other information, onto a single customized report.
"We believe Scheduler is helping simplify our processes by prioritizing work orders and sharing raw materials between Twinsburg and other plants," said Reynolds. "Rockwell Automation is now better able to synchronize the supply chain, both internally and externally, therefore prioritizing activities according to standardized business rules that can be uniformly followed across the enterprise."
"Beside improving how we utilize available manpower, Scheduler helps us gain better use of workers'' best practices and get more flexibility of product and staff," said Stettler. "Manufacturing associates can make better decisions based on actual information rather than gut feel.
"And communication across the supply chain has improved tremendously. That fits in with our goal of helping associates do their jobs better by accessing the information they need and easily sharing it anywhere in the company, from shop floor to top floor."
Reynolds added, "If workers are set up efficiently, they''ll perform optimally. We don''t believe in permanently putting one person in one role. We''ve cross-trained our associates so they can go where the work is. Scheduler lets us see constraints on the floor and know where to move people."
Eradicating manual methods and automating certain assembly procedures lets Rockwell Automation''s associates focus on value-added work. As an indication of time savings, Scheduler has helped save roughly 100 hours person-time per week by reducing the time invested in generating production schedules.
The implementation of Scheduler has also impacted customer satisfaction, as Scheduler contributes to Rockwell Automation''s pledge to deliver product to customers 90% on-time-to-want. "That means nine out of ten items will meet the on-time-to-want date," explained Reynolds. "Scheduler is moving us toward that goal by optimizing our available resources so that we deliver what customers really want, when they want it."
Between the Twinsburg and Dublin facilities, Rockwell Automation projects savings of over $500,000 annually. Considering that a typical Scheduler solution costs roughly $125,000, the company estimated that it would be paid for within eight months.
"Given our mix of products," said Reynolds "we couldn''t have gone from cellular layout to flow layout without Scheduler. If you don''t have Scheduler, you''re running an inefficient job shop."
For an ARC Advisory Group study of the Twinsburg and Dublin plants, available in .pdf format, click here. The study was undertaken to answer the question, "How do automation suppliers, who are also end-users, automate their own manufacturing facilities?"
To obtain Adobe Acrobat Reader, click on the link below.
