Original Date: 07/08/2003
Revision Date: 01/18/2007
Information : Machine Shop Estimating
Users of Machine Shop Estimating software must have basic machining knowledge. The software promotes accuracy and consistency while reducing the time required to complete a cost estimate. Utilization of CAD files to describe the product greatly improves customer responsiveness and further reduces manufacturing costs through automatic generation of the cost estimate and CNC files.
In the past, In Tolerance manually prepared manufacturing cost estimates using paper forms and calculators. Although the estimates were prepared by a knowledgeable person with a good understanding of the machine shop, the procedure required several hours or days and was subject to variances due to items such as machine selection and tool choice. After a lengthy search for a better way to provide estimates, In Tolerance chose Machine Shop Estimating (MSE) in early 2003.
MSE is a Microsoft Windows-based software package that creates cost estimates that can be tailored to the individual production facility. The cost estimate is more likely to be accurate since it is built using the actual capabilities of the shop floor equipment. The machines in the shop are characterized by parameters (e.g., capacity, speed, horsepower, feed rates, load/unload times). Customizing the software to accurately represent the shop floor is not a trivial task; however, the up-front effort results in improved accuracy and consistency for the subsequent cost estimates.
The appropriate machines, or work centers, are chosen from a table of those listed on the screen to construct a job routing. MSE calculates the tool path from the part geometry and the tool description. Unique costs for processes such as heat treat, inspection, or plating can be entered as desired. MSE contains a library of more than 1,000 materials with their associated speeds and feeds. These are used to calculate machine times, but like all parameters, may be overridden if necessary.
A material cost library contains the costs for many different materials as well as associated information such as minimums and shipping charges. An on-screen link to a Website is also available where real-time pricing can be obtained. MSE offers labor detail down to what is essentially a method-time-measurement standard (e.g., reach, grasp, insert, turn), and labor rates are entered as desired. An efficiency factor can be applied to account for real- world inefficiencies such as rest periods, part complexity, and learning curves.
The MSE software is relatively new at In Tolerance, and is being used in parallel with manual cost estimating until the customization process is complete, at which time the software will accurately reflect the machine capabilities and other variables that make the shop unique. In its present use, MSE performs in a similar manner to the manual process, but with improved speed and consistency. Substantially greater gains will be realized in the future, when a solids model file will be used to describe the machined part. MSE can then read the CAD file, and using automatic feature recognition, generate shop floor routings, tool paths, cost estimates, and CNC files.
In Tolerance has already begun to realize the benefits of using MSE, and those benefits will expand with the use of CAD files to describe the parts. Reduced time to prepare a cost estimate is one major benefit, and accuracy has been improved due to a reduction in the variables and human involvement. In Tolerance prides itself in customer responsiveness. Estimates that used to take hours or days can now be completed in a fraction of the time, and same- day quotes will become practical. Since the machine capabilities and rules are defined, the estimates will provide realistic shop floor routings with consistent results from one job to the next.
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