This book constitutes the thoroughly refereed post-conference proceedings of the 13th International Joint Conference on Software Technologies, ICSOFT 2018, held in Porto, Portugal, in July 2018. The 18 revised full papers were carefully reviewed and selected from 117 submissions. The topics covered in the papers include: business process modelling, IT service management, interoperability and service-oriented architecture, project management software, scheduling and estimating, software metrics, requirements elicitation and specification, software and systems integration, etc. .