He earned his master’s degree in Electrical Engineering from Chalmers University of Technology (Chalmers tekniska h gskola) in Gothenburg in 1962 and a doctorate from the Royal Institute of Technology (Kungliga Tekniska H gskolan) in Stockholm in 1985 with a thesis on language builder for large real time systems. In 1967 he proposed the use of software components in developing the next generation of controlled telephone switches, which Ericsson was developing. This invented sequence diagrams and collaboration diagrams developed. Also implemented state-transition diagrams to describe the message flow between components. He thought it was necessary to make software development plans and was one of the original developers of SDL (Specification and Description Language). In 1967, SDL became a standard in the telecommunications industry. He also invented use cases as a way to specify functional software requirements.In April 1987, he left and founded the company Ericsson Objective Systems. A majority of the shares of the company was acquired by Ericsson in 1991 and the company was renamed Objectory AB. Ivar Jacobson developed the software process in Objectory OOSE AB around 1992. In October 1995, Ericsson AB sold for signature Objectory Rational Software, and Jacobson started working with G Booch and James Rumbaugh to first create the Unified Modeling Language (UML) and later develop the Rational Unified Process (RUP). In 2003, Rational Software was acquired by IBM and Ivar decided to quit, but he remained with the company until May 2004 as executive technical consultant. In mid-2003 formed Ivar Jacobson International (IJI), an umbrella company for Ivar Jacobson Consulting (IJC) which operates across 4 continents and has offices in the UK, USA, Scandinavia, China, Korea , Singapore and Australia.In November 2005, Jacobson announced the Essential Unified Process (EssUP), a new “practice” focusing on the software development process. This is a new beginning for the integration of effective practices among the three main areas of process: the unified process, agile methods and process maturity. Each of them contributes different capabilities: structure, agility and process improvement. EssUP Jacobson has described as a “super light and agile.” ORs and the IJC have EssUP integrated into Microsoft Visual Studio Team System and Eclipse.