Information technology suppliers are companies or vendors that specialize in providing various information technology-related products, services, and solutions to businesses and organizations. These suppliers play a crucial role in helping companies meet their technological needs and objectives. Selection of the right information technology supplier is crucial for the success and efficiency in business operations. Selecting the right information technology supplier for service companies requires careful consideration of specific factors relevant to the nature of service-based businesses. By prioritizing these factors such as industry experience, scalability, service-oriented solutions, integration capabilities, mobility, data security and conducting thorough due diligence, it can be select an information technology supplier that understands the unique needs of service companies and can provide tailored solutions to support business growth and success. In this paper, dynamic fuzzy multi-attribute decision making for supplier evaluation and selection in service systems is developed using Z-number. Z-numbers provide a more nuanced representation of uncertainty, incorporating both the value and its reliability. By considering reliability, decisions are based on more robust and credible information. The model can adapt to dynamic changes, making it suitable for environments where conditions evolve rapidly. Using a dynamic fuzzy evaluation matrix expressed in Z-numbers, the decision information is fully described, and using ordered entropy weights, selected the best supplier for service systems.