When installing new equipment and other tasks related to computer technology, must also be specification. Let it be very short, consisting of just a few suggestions, but still it must necessarily make. Otherwise, you risk getting a device that you do not absolutely necessary. For example, if you want to buy a scanner to enter into the computer page of the book, then this should be stated in the specifications. If you want to automatically enter a number of separate sheets from the stack, then it should also be reflected in the job.
To meet these challenges requires a totally different hardware, and if you just say that you need a scanner, you will likely get a different machine than what you need. The TOR should be describe in detail what you want to get a result. More than all will be explained, the easier it will accept your work. In some cases, already at the stage of formulation of the problem becomes clear that your requirements feasible. In this case, adjust or abandon their plans.
If you have not worked for the terms of reference, you can learn about the impossibility of implementing your ideas, when you bring the finished product, absolutely you do not need. In setting up the job very well have an idea of how it can be done. For example, giving the job to connect you to the Internet, it is desirable to know how to do it. If you do not have representation, then some unscrupulous employees can offer you an uncomfortable option for too much money.