This IDC study is a translation of the Japanese document IDC #JPJ42862717. It presents the Japan SMB IT market performance in 2016 and market size forecasts from 2017 to 2021 by company size, product, and industry, by considering the latest economic situation and product information gained from vendor surveys conducted until March 2017. From this study, IDC made changes to the Japan IT market product classifications following the changes in the product classifications in the IDC Worldwide Black Book. These changes include the separation of the hardware market into device market and infrastructure market, the addition of infrastructure-as-a-service (IaaS) segment to the infrastructure market, and the addition of the business service market. IDC also refines the company size further by separating the "1 to 99 employees" class into "1 to 9 employees" and "10 to 99 employees" classes. Now, there are five company sizes (formerly four company sizes). IDC predicts positive growth in the Japan small and medium-sized business (SMB) IT market. However, this growth will be driven by the newly added business service market, IaaS market and the PC market, while growth in the server, storage, and IT services markets will remain relatively low. This trend shows that changes are taking place in SMB spending trends. "IT suppliers should review their SMB-oriented businesses in anticipation of the changes in SMB IT needs taking place in the Japan SMB IT market," says Hitoshi Ichimura, research manager, IT Spending, IDC Japan.