Nowadays, computer plays a very important part in human’s life. Computers are everywhere in society today – at home, work, hospital and many more. Most daily activities either involve the use of or depend on information from a computer. Thus, Information Technology is growing rapidly and pacing fast. In order to improve the efficiency of the current system with the aim to be more users friendly and easier to use, I would like to enhance the purchasing system in Padja Raya Motor, Tangerang. This fieldwork report is written based on the purchasing system in Padja Raya Motor, Tangerang. The computerized purchasing system is enhanced according to my experience of work in that company. System development approach is used in developing that system. The report discuss throughly on the processes involved in the company’s purchasing system. Process modeling and data modeling concepts are the fundamental theories that are applied in this fieldwork. Process are described by using DFD, each data is explained in greater detail by using data dictionary.