A BPM system is described for modeling, management and execution of business processes. A process designer component is used to graphically design a business process, which includes a set of activities linked by transitions. The business process is stored and executed using one or more engines. A mobile device can be used to access the business process instance executing on the engine. The mobile work portal can be generated to render information for the process instance onto the mobile device. A process application programming interface can be used to access and manipulate the process instance from the mobile device.