SAP is an ERP application which is mainly used for automating all business activities with integration. The concept ERP says Enterprise Resources Planning.  SAP does the same, like in normal course of business we get lot of cross functions while doing our own work say in Materials department.  When we have to raise the request we have to see the possibilities of demand of end products, sales in the previous years, prices of materials weather to make or buy? and lot other things.  Once we take the position of goods we got to pay the vendor, here usually the Finance department comes into picture and takes care of payment.  
For doing these activities in a normal (real) business senario it would take at least 2 to 3 weeks time to collect the information and take decisions and organizing things.  But in SAP application the time factor reduces.  It become to 1 day for knowing information and do things, or it might take less time that depends on the company's policies and procedures. The level of acuracy in information is extreemly good.  The integration part as explained in above example the connection between the departments as they follow in their company.  If Materials department raises an order the check will be done before raising order (S&D department would have updated the status in system which can be viewed) and getting goods, then immediately the finance department will take the further actions about it.   _{Your Comment}