A product or products whose sales amount is less than a expected amount in a dealer of the company is treated as lost sales. Most companies want to identify these kind of products and increase the sales of these products through methods such as campaigns and discounts for these products. With this project, it is aimed to determine the loss sales by using machine learning teqniques.

To achive that, various dataset to be used in the training and testing of the system are collected. There should be a product-dealer relationship in this data. For this issue, the relationship has been paid attendion when the data collected.

After the data collection process has been completed, changes have been made to the existing data for learning phase of the system. Then, when the data is ready, the system is trained with machine learning techniques and with Web interface the user of the system was required to have the necessary information and data entered into the system. Then the system can return results according to the inputs.