Hi, the stacked bars are odered by order of attribute (“service” in your case) and items in the legend follow the same order. It helps readibility of charts. The order of values of attribute
can be customized in data model. You can add column to dimension dataset, which contains attribute values and set it as “sort label”. For example you can use values 1,2,3 in this extra column for priorities High, Medium, Low if this is the desired order. GoodData then uses this extra column for sorting of the values which are displayed.