A Java File Security System (JFSS)  has been developed by us. That is an ecrypted file system. It is developed by us because there are so many file data breaches in the past and current history and they are going to increase day by day as the reports by DataLossDB (Open Security Foundation) organization, a non-profit organization in US so it is. The JFSS is evaluated regarding the two software engineering approaches. One of them is size metric that is Lines of Code (LOC) in the software product development. Another approach is the customer oriented namely User Satisfaction Testing methodology. Satisfying our customers is an essential element to stay in business in modern world of global competition. We must satisfy and even delight our customers with the value of our software products and services to gain their loyalty and repeat business. Customer satisfaction is therefore a primary goal of process improvement programs as well as quality predictions of our software. With the help of User Satisfaction Index that is calculated for many parameters regarding the customer satisfaction. Customer Satisfaction Surveys are the best way to find the satisfaction level of our product quality.