A server computing system stores at least one workflow template and at least one workflow customization table. The workflow template includes activity elements that indicate activities included in the workflow. The activity elements include attributes associated with input properties of the indicated activities. At least one of the activity elements includes an attribute associated with an input property, the attribute specifying a variable name, not particular data. The workflow customization table includes an entry associating the variable name with particular data. When the server computing system initializes a workflow instance based on the workflow template, the server computing system binds the input property to the particular data specified by the workflow customization table. Thus, by storing different workflow customization tables, the same workflow template can be used to initialize workflow instances having different behavior.