Unified Modeling Language (UML) is accepted as the standard for modeling software designs and is commonly used in software development Thus this paper investigated the practice of Junior and Senior Business System Developers in the use of UML and other Diagrams. Part of the study is the UML Systems modeling usage for Junior Developers by investigating the documentation used in development. This study used several methods in gathering data, interview, and questionnaire from junior and senior developers was used to come up with a result. It also investigates the possible usage of UML Diagrams in Business field which will be a basis for a future proposed content curriculum for both Business Administration and Information Technology. The result of the study shows that junior developers are not using UML Systems modeling, while senior developers increase as the experience increase in development. Most of the respondents used a diagram that is outside in the UML family. The study also shows that UML helps the managers and business people to build models and diagram that helps them to put things into perspective. It proposed that UML Diagrams should include in business Subject for both programs, the business and information technology program should unite to increase the UML usage.