Computer-implemented method for securely executing a workflow in a computer system that comprises at least one distributed repository network and a number of client systems which are or can be operatively coupled to this repository network, wherein - a model of the workflow is stored in the repository network, - the model of the workflow comprises a number of workflow steps, wherein a predetermined workflow step is defined as an initial step which is executed as a first step when executing the workflow in the computer system, and wherein for each workflow step in the model of the workflow the following are stored - execution conditions that must be met for executing the workflow step in the computer system, - events which are recorded when executing the workflow step in the computer system, - tasks assigned to a user, a user role or a client system when a workflow step is executed in the computer system, - notifications provided to a user, a user role or a client system when a workflow step has been successfully executed in the computer system or when a workflow step needs to be executed in the computer system, and - information about a number of actions, - for executing the workflow in the computer system, a workflow instance which represents the workflow to be executed is generated from the model of the workflow, wherein the workflow instance is stored in the repository network, - when executing the workflow instance in the computer system - initially the initial step and subsequently the further workflow steps are executed, wherein the actions are executed during execution of a workflow step, - when starting a workflow step, the events, the tasks, the notifications and, based on the information about the number of actions, the actions are generated and stored in the repository network, - state data are stored in the repository network for each executed workflow step, and - a workflow application executed on at least one client system - receives notifications from the repository network which were stored in the repository network for a predetermined user, and - executes, for a workflow step to be executed on the at least one client system, a program code assigned to the workflow step. - a model of the workflow is stored in the repository network, - the model of the workflow comprises a number of workflow steps, wherein a predetermined workflow step is defined as an initial step which is executed as a first step when executing the workflow in the computer system, and wherein for each workflow step in the model of the workflow the following are stored - execution conditions that must be met for executing the workflow step in the computer system, - events which are recorded when executing the workflow step in the computer system, - tasks assigned to a user, a user role or a client system when a workflow step is executed in the computer system, - notifications provided to a user, a user role or a client system when a workflow step has been successfully executed in the computer system or when a workflow step needs to be executed in the computer system, and - information about a number of actions, - for executing the workflow in the computer system, a workflow instance which represents the workflow to be executed is generated from the model of the workflow, wherein the workflow instance is stored in the repository network, - when executing the workflow instance in the computer system - initially the initial step and subsequently the further workflow steps are executed, wherein the actions are executed during execution of a workflow step, - when starting a workflow step, the events, the tasks, the notifications and, based on the information about the number of actions, the actions are generated and stored in the repository network, - state data are stored in the repository network for each executed workflow step, and - a workflow application executed on at least one client system - receives notifications from the repository network which were stored in the repository network for a predetermined user, and - executes, for a workflow step to be executed on the at least one client system, a program code assigned to the workflow step.