Industrial control and automation have been historically dependent on hardware devices and proprietary, vertically integrated systems. Shifting the centralization of logic and intelligence from hardware into software that can run on any capable device is a key step in improving productivity and flexibility in manufacturing. This shift also addresses common challenges that all manufacturing industries face, such as an aging, skilled workforce and increased demand for product personalization. Manufacturing companies need to adopt best practices from the IT domain to enhance their operations and provide support to automation engineers. This report analyzes the concept of software-defined automation (SDA) and its relationship with software-defined networking (SDN) and software-defined manufacturing (SDM). It examines the current and anticipated developments in virtual programmable logic controllers (vPLCs) in manufacturing and provides an analysis of the competitive landscape, along with predictions for the future. The report also explores the relationship between SDA and cybersecurity, as well as SDA and AI. The study identifies the factors driving and restraining the growth of SDA solutions and highlights the opportunities emerging from the changes in this space for market players and stakeholders to leverage.