Quality management is a hot issue in most organisations and must be considered in the business processes of the organisation. Existing approaches on business process modelling provide neither explicit strategies to model quality requirements on business processes nor do they provide explicit support for the construction of business processes satisfying such quality requirements. In this paper, we present a patterndriven development process for modelling business processes with respect to given quality constraints. We introduce a visual pattern specification language based on UML Activity Diagrams that enables the expression of quality constraints as patterns. These patterns can be used in a forward-engineering development process which supports the business process designer in constructing business processes by applying patterns. Thereby, quality constraints can be integrated into the design of business processes seamlessly.