ComputerAided Process Planning What is CAPP Design approaches of CAPP systems Retrieval CAPP systems/ Variant CAPP Generative CAPP systems Variant (Retrieval) CAPP Methodology Variant CAPP Variant CAPP Variant CAPP Generative CAPP Methodology CAPP Model CAD systemPreprocessor Postprocessor Production planning and Scheduling Knowledge InputCAPPOutput Planning rules CAPP Model Advantages of Generative Process Plan :

1. They rely less on group technology code numbers since the process, usually uses decision tree to categorize parts into families. 2. Maintenance and updating of stored process plans are largely unnecessary. Since, any plan may be quickly regenerated by processing through the tree. Variant or Generative? A variant system is better for manufacturing setting where similar parts are manufactured repetitively. Because parts are similar, Group Technology can easily be implemented and shows quick and significant return on investment (ROI). Because similar parts are produced repetitively, process plan can be retrieved, slightly modified and used, without going through too much trouble. A Generative process planning is better suited for a manufacturing environment in which part does not exhibit too much similarity and new part are introduced on a regular basis. In this case, benefits cannot be gained from Group Technology due to dissimilarity of parts. Because, new parts are regularly introduced, historical data does not have too much value to the process planner.Benefits derived from CAPP : Process rationalizationand standardization Increased productivity of process planners Reduced lead time for process planning Improved legibility Incorporation of other application programs Recent trends in CAPP systems include : 1. Automated translation of the design dimensions.2. Tolerances into manufacturing dimensions.3. Tolerances considering process capabilities.4. Dimensional chains.5. And to make CAPP system affordable for small and medium scale manufacturing industries.15 Shop Floor Control Definition: Shop Floor Control (SFC) is the process by which decisions directly affecting the flow of material through the factory are made. Functions: WIP Tracking Throughput Tracking Status Monitoring Work Forecasting Capacity Feedback Quality Control Material Flow Control The Shop Floor Control System The three steps or modules are: 1. Order release 2. Order scheduling 3. Order progress Order Release: The purpose of the order release module is to provide the necessary document that accompanies an order as it is processed through the shop. These are referred to collectively as the shop packet 1.Route sheet-listing the operation sequence and tools needed 2. Material requisitions-to draw the necessary raw materialfrom stock 3. Job Cards-enough job cards to report the labor for each operation on the route sheet 4. Move tickets-to move the parts between work centers 5. Parts list-for assembly jobs Order Scheduling: The purpose of order scheduling is to make assignments of the orders to the various machines in the factory. Inputs to this module consist of the order release and priority control. The basic document prepared by the order scheduling module is the dispatch list. It reports the jobs that should be done at each work center and certain details about the routing of the part. Order Progress: The order scheduling module satisfies the first function of shop floor control.The purpose of the order release module is to accomplish the remaining three functions of SFC. The order progress module maintains a file of the transactions reported on each of the uncompleted jobs. This file is called the open order file, and it contains the latest status of each job order in the factory. The types of reports that can be generated from the open order file include the following: 1.Work order status report 2.Exception Report Used to collect data in material handling and manufacturing applications -In material handling, the applications include shipping and receiving, storage, sortation, order picking. - In manufacturing, the applications include monitoring the status of order processing, work-in-process, machine utilization, worker attendance. The principal components of automatic data identification technologies: 1) Encoded data 2) Machine reader or scanner 3) Decoder Automatic data identification methods - The light reflections are sensed by a photoconductor, which converts the spaces into an electrical signal and the bars into absence of an electrical signal. - The width of the bars and spaces is indicated by the duration of the correspondingsignals - The decoder analyzes the pulse train to validate and interpret the corresponding data Bar codes The symbol consists of bars and spaces of varying width. The pattern of bars and spaces is coded to represent numeric or alphanumeric charecters. Radio frequency identification Magnetic stripes Optical character recognition Machine vision system