In consumer devices, like digital television sets or set-top boxes, there can be a problem with a sudden load increase caused by for example a scene change and user focus. During such a load increase, the quality of service of the application having the user focus will decrease until the device detects the load increase. The device can reallocate resources to the application having the user focus after which the quality of service will increase again towards its previous level. However, the user may have noticed the quality decrease. In order to prevent this noticeable decrease of quality in overload situations, a method and a system are provided that guarantees a worst-case budget to the application having user focus and conditionally guarantees a budget surplus to an application not having the user focus. The latter application can then use that budget surplus to operate at a higher quality of service level.