The products that we see in the markets today are very complex and demand such high quality for surface finish and accuracy, which cannot be obtained by manual machining on conventional machines. We need to use High precision CNC machines for machining them.
 CNC machines are machines which allow the motion and control of the tables and tool movement in various directions, by means of a controller input with digital programming codes, called as G and M codes, or CNC Programming codes, containing the details required for the X, Y, Z motion, cutting speeds and feeds. They also have an account of the Cutter rotation, tool number and tool changing, rotation, etc. along with the Program number, line number etc.
 For the past several years, the CNC Programming codes have been written manually by CNC Programmers. This is however a very cumbersome task, since the programmer has to go through a massive amount of calculations, considering simultaneously design parameters, tool parameters such as size, offsets etc, machining parameters, and also process sequence for roughing, finishing etc. After generating the CNC Program, it has to be checked thoroughly for any errors of possible tool gouging. It is a common practice to first do the machining on wood, plastic or wax, before actual machining on the desired product material or tool steel. This is done to ensure correctness of the code and avoid wastage of costly material. However this process of prototyping consumes a lot of time and money and resources.
 Once the Programming code is ready, to be used either for Prototyping or actual machining, the programming codes have to be entered into the controller. Note that the programming codes are controller specific, since they have been designed, keeping in mind a specific input format for a certain controller. We are thus not flexible to use the codes on any other machine with any other controller.
Entering CNC codes into the controller is a tedious job, and can result into a number of errors if the proper care is not taken. Besides this, all the codes can not be entered into the controller at once, since the controller has a memory limitation. Thus, the operator has to repeatedly enter, machine and delete the codes to complete the entire machining. Besides, after the prototyping, if there is any change in the model, tools, cutting parameters, or the controller, the programmer has to rewrite the entire codes for the new conditions. Even if there is no change, still the operator has to go through the same cycle of entering codes for the final machining.
 Thus conventional methods of machining cause a lot of inefficiency and waste of time, money and resources. This is where a CAM package comes to our rescue.

 A Computer Aided Manufacturing package makes the entire process very simple. First we select the 3D CAD model, or the surfaces to be machined. The model can be imported from any other CAD package, or else can be completely created in 3D using the same CAD package. We then select the appropriate process sequence i.e. roughing and finishing. For each of these, we define the suitable tool type and parameters. Tools can be either selected from a library of standard tools or else, we can also create a custom tool as per our requirement.
The Package then allows us to select from a variety of machining types. We have to enter in cutting parameters such as Feed, speed and cut tolerances, depending on the type of machining to be done.
The CAM package takes in all these inputs and automatically generates the toolpaths for machining. It also shows a Backplot and Solid verification to check the accuracy of the code. The toolpaths, after being accepted, are saved in the system as an intermediate NC file. Now, we have to post process this file, based on the controller of the CNC machine on which we plan to carry out the machining.
 The software asks us to select from a library of standard post processors or allows us to create our own post processor. The post processed file is the CNC program file which has to be fed to the CNC controller for carrying out the machining.
 One of the major advantages of a CAM package over conventional programming, is that in case of any change in the model, tools, parameters, or even the controller type, we just have to make the changes in the model, go to the operations manager, maket the appropriate changes in the parameters, and the software give us an output of the updated toolpath, the NCI file, and the CNC code. This avoids a lot of rework.
 After generating the CNC codes, the CAM package gives us an option of sending the entire CNC code to the controller directly via the RS 232 port which is there both on the P.C and the controller. Based on the controller memory limitations, we define the batch size, and the baud rate, after which the package sends the code to the controller for machining.
 The CAM package also gives us a Setup sheet output, which is a printed format with details on the process, tools used, parameters, and also mentions the time required to complete the machining.
Thus, we have seen how a CAM package eliminates a lot of problems encountered in the conventional/ manual method of CNC programming,and builds in accuracy, integration and productivity into the entire process.
 In the years to come, it is clear beyond doubt that Engineering software will play a vital role in the entire manufacturing process. A very important area, which remains largely neglected, is the availability of engineers skilled at using CAD/CAM products. A number of companies now need engineers with such skills. With a number of companies marketing CAD products rising, it is obvious that the demand for people specialized in CAD/CAM will rise.
Apart from the Engineering Industry in India, there are tremendous job opportunities in companies, which offer consultancy services to companies in India and abroad. A number of skilled CAD/CAM designers go to the U.S. every year for working on large design projects.
 Since all the CAD/CAM packages are built on similar technology base, use similar methods of model creation and functionality built into them, it is sufficient if an individual learns one high-end package. Later switching over to another software is very easy, and just needs a day or two to familiarize themselves with the new icon structure and user interface.
 I-DEAS and Mastercam, are world leading CAD/CAM packages, which have capabilities of 3D modeling and CNC programming. They offer a variety of features, which make the job of CNC machining easier, accurate and flexible.