Single Source Approach Saves Millions
Since introducing its first printers in 1984, Hewlett-Packard (HP) has shipped 230 million of them, including 130 million inkjet printers and 60 million laser printers. The HP imaging business is currently shipping 30 million inkjet and 7 million laser printers a year, generating revenues of about $20 billion.
Since introducing its first printers in 1984, Hewlett-Packard (HP) has shipped 230 million of them, including 130 million inkjet printers and 60 million laser printers. The HP imaging business is currently shipping 30 million inkjet and 7 million laser printers a year, generating revenues of about $20 billion. Power Engineers Inc. (Boise, ID) helped HP implement a standard communications interface between the control systems and the numerous software packages that direct and monitor plant operations for contract manufacturers producing LaserJet printers around the world.
Standardized data and interfaces are now used on the highly automated assembly line at the HP LaserJet printers manufacturing facility in Boise, ID.
''Giving single source responsibility for all automation layers, and their interfaces, to one supplier was the key to achieving major improvements in productivity and downtime,'' says Jason Wright, IT Segment Lead for HP (Boise, ID).
Many LaserJet printers are built using highly automated manufacturing systems that are controlled primarily by Allen-Bradley programmable logic controllers (PLCs) from Rockwell Automation. Each system is somewhat different, employing various kinds of input devices and analog and digital I/O points. The challenge was to standardize the data and the interfaces across the controls, the supervisory control and data acquisition (SCADA) layer that manages the individual PLCs, and the manufacturing execution system (MES) layer that provides recipes and instructions to control systems and collects manufacturing data. In the past, each layer was the responsibility of a different vendor. When problems occurred, the vendors often pointed fingers at one another, and it was very difficult to determine where the actual problem lay. The result was that systems-related downtime was far too high, as high as 12% in some plants.
HP originally brought in Power Engineers to customize the SCADA application and to improve its flexibility. After succeeding with that, the decision was made to turn over to Power the PLC programming tasks, which were originally the responsibility of a conveyor company. As Power began working on both the PLC and SCADA levels, problems were reduced and the company tracked down and resolved several nagging issues that had previously fallen between the dividing line of the two vendors that had supported these systems.
Cleaning up the MES
Later, when HP personnel decided to replace the patchwork of different MES schemes used at various facilities with one system, they selected Piñata, an open source MES solution originally developed at the HP Netherlands plant, because of its low cost and flexibility. As customized by Power Engineers, Piñata provides a unique approach and integrates easily with the various line control systems.
As part of this project, a Power Engineers team developed generic interfaces for the PLCs and other control devices used in the contract manufacturers' plants. The interface is based on the Object Linking and Embedding (OLE) for Process Control (OPC) standard and can easily be extended to other types of controls. Using Borland Delphi, the team wrote OPC clients that communicate between the PLCs, SCADA system, and MES. The interfaces were written and implemented in about 4-6 weeks. They work so reliably that HP could stop measuring downtime because there wasn't any to measure, even though the system runs on a 24/7 basis at some plants.
''The reliability of the new interfaces and single-source support has substantially improved our uptime,'' Mr. Wright adds. ''In addition, the higher performance of the new MES has improved the trickle rate, which is the average interval between units coming off the line, by better than 50%. We have seen annual savings to date of $1.5 million at each of three U.S. plants that have implemented this system, while savings at other plants are averaging half this amount.''