Original Date: 06/05/2006
Revision Date: / /
Best Practice : Billware Software Suite
The Billware software suite used in the Rockwell Collins Coralville facility provides a means for integrating the scheduling, setup, and production aspects of its surface mount technology production lines. Implementation of the software has resulted in increased assembly traceability, decreased paper consumption, and reduction in redundant data entry, creating significant throughput improvements due to data mining capability.
The Rockwell Collins Coralville facility has six Surface Mount Technology (SMT) manufacturing lines. Prior to 1999, the facility did not have a system that integrated line balancing and scheduling with the running of these SMT lines. Scheduling was mainly handled through handwritten tracking sheets, making real-time changes on the production floor difficult to handle. There was no established method for tracing history and past quality issues for assemblies previously run on these lines, forcing engineers to rely on memory or manual records to prevent historical defects from recurring. Because there was not a good systematic way of flagging problems with current lot runs, the process of stopping machine or process problems from affecting an entire lot of parts required constant human vigilance.
These problems were compounded by pick-and-place machines on the SMT lines that required excessive load times due to the manual process involved for finding in-process material. If a reel was needed and could not be found on the production floor, it could be located either in one of the SMT lines, in the parts carousel, or in a tote on its way to the parts carousel. Multiple reels for the same material would be used interchangeably, and parts would occasionally be stored in the wrong locations, creating the need for a process in which multiple people checked part locations on a regular basis.
Several other processes, including oven and electrostatic device (ESD) logs, missing parts, and run-and-hold (R&H) tags, were handled manually and highly prone to human error. Oven logs were handwritten and required the operator to both calculate the time a product should be removed and remember to remove it at the prescribed time. The Coralville facility requires operators to check their ESD straps twice a day. Prior to 1999, the ESD logs were handwritten. It occasionally becomes necessary to run assemblies through the SMT lines with red-lined assembly drawings before a change is officially approved, a process that previously required operators to manually label R&H tags to signify that the product had been built to a new revision. Handwriting these tags caused operators to spend a significant amount of time away from running product when large lot sizes were involved. Errors in writing or attaching missing part tags also contributed to defects and unnecessary rework.
The Billware software suite, developed in 1999, is a Visual Basic-based control panel that facilitates functionality to data stored in an Oracle database. It provides a means for scheduling product, tracking defects, and quickly identifying errors in the SMT process as they occur. The software’s scheduling module provides a snapshot of the assemblies currently running in the area and identifies their specific location on the SMT line. The scheduler uses contract’s date information from the facility’s SAP enterprise resource planning system to schedule upcoming builds. Although the software-determined sequence is generally used, the production coordinator in the facility has the ability to change the build sequence or move an assembly to an alternate available line if problems arise.
The software also provides the capability for managing stock and set-up queues to aid in scheduling. The scheduler interfaces with the pick-and-place machines to retrieve bill-of-material information and uses this information to track which parts need to be ordered and which reels need to be set up on the feeders for a particular assembly to be ready for build. It cross-references common parts between lines and includes a screen for printing labels so that reels can be visually located on carts or on the pick-and-place machines, reducing operator time spent searching for reels. The software database stores historical data for all runs for an assembly for up to three years, making information such as build times and problems encountered accessible in each successive build. Process engineers can log specific information regarding previous defects into a “hit list” and flag assemblies for future production runs until the issues have been resolved. The availability of this and real-time run data have allowed the Coralville facility to make significant throughput increases without the purchase of a sizeable amount of new equipment.
The Reel Management module within Billware software has improved the efficiency of the set-up process and diminished the amount of time operators spend looking for reels. The Reel Manager logs all possible locations of reels, including in-transit, SMT line number, and carousel location. It also includes an error-tracking system that reduces the possibility of a wrong part being placed on a board and displays the color label of the reels associated with a particular assembly, making reels easier to obtain. A common reel list for frequently used feeders is contained in the software database, which helps to eliminate the waste incurred on the reel with each successive setup. The program also stores the reel’s serial number to have traceability in the event of a defective vendor lot. Each time there is a change in the status of the reel (i.e., it is emptied or pulled out for engineering evaluation), the change is logged into the system.
The Billware suite also includes programs for handling oven and ESD logs, missing parts, and R&H tags. Using the oven log program, operators enter the time they put an assembly into an oven, and the oven required out-time is automatically calculated. In addition, operators are flagged when the out-time has been reached, decreasing the chance of overbaking an assembly. The ESD log program in the software automatically reminds operators to test their ESD connections, increasing individual accountability. Tags for missing and R&H tag information are generated through another module in the software. In the event of a large production run, the missing part and R&H tag programs greatly decrease former duplication time due to available copy-and-paste functions. Data mining on missing part incidences is also greatly facilitated through the use of the Billware suite. The software has resulted in approximately $2 million in cost avoidance for the Coralville facility.
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