All module in here is based on odoo 9.0
An example module to add workflow to a model or object, implementing sub workflow and using condition in transition.
An example of inherit, adding functional to existing module, module Website Support from OCA (https://www.odoo.com/apps/modules/9.0/website_support/) is used as existing module. Additional functional consist of adding SLA, PIC schedule and email notification, and category of ticket.