P PT. Sanggar Sarana baja is a company that has activities in steel construction field . This company produces several industrial equipment such as for oil, gas and petrochemical, especially on producing heavy equipment, pressure vessel, cooler and steel pipe and non steel pipe assembling. In this final assignment research, it has been studied about case on the material plate as a main raw material. On choosing potential supp.ier, Nowadays, PT. Sanggar Sarana baja is not evaluate supplier performance data in the past. Therefore, it causes the decision that has been take was not maximal. To so1\'.re the problem, it can be used a supplier evaluation method based on criteria of quality, quantity, delivery , term of payment and flexibility and information system design to evaluate and supplier selection. The first step to evaluate the supplier is to find the value of each criterion on supplier selection by using Analytical Hierarchy Process (AHP) method. This value is based on questioner that has been spread to the company expert . From the processing of that method, it can be known the value foe each criteria above those are 0.325; 0.228; 0.175; 0.146; 0.084; 0.042.The data is proceeding with those 6 criterions, to ensure the performance of each supplier. It can be done by multiplying average value of each criteria based on purchasing on July - September 2005 with the value that has been got from AHP calculation . The whole value result will determine the rank of potential supplier for example for supplier 2 on the top rank with value 4.88, followed by supplier 5, supplier 1, supplier 3, and supplier 4 with total value total 4.755; 4.693; 4.686; and 4.603.To make those thing easier and can get maximum result on supplier evaluation, ithas been designed an information system that is connecting between production department , purchasing and inventory . After several test on information system that has been designed, it can be got the same result as manual calculation . After knowing the supplier evaluation result on 5 October 2005 is found a request from production division to purchase material plate SFT X 20 FT X l 6:MM., Plate 5FT X 20 FT X l 2rv1M, and Plate 6FT X 20 FT X 12MM. The calculation was done based on supplier evaluation result from6 criterions above, except for criteria of value price that is based on price per unit nowadays. From the result, it can be known that the 2nd suppiier was chosen to get the order from the company for 3 materials above. By using calculation based on information system design that has been made it can be got the same result. It proves that this information system design can be used as its function.