Halliday & Matthiessen (1999: 148-9):
If the process is dispositive, the outcome is more variable; it may be either (i) a figure of doing (more specifically, doing [to]/happening), or (ii) a figure of being (more specifically, being [at]/having):(i) the cat chased the mouse outcome: ‘the mouse ran’(ii) the boys mended the roof outcome: ‘the roof was whole’John gave his sister a violin outcome: ‘John’s sister had a violin’[The being outcomes] may be elaborative (intensive), extending (possessive) or enhancing (circumstantial). …
Notice that in some cases the outcome is embodied in the clause by which the figure is realised; for example in middle variants of the doing & happening type (the outcome of John ran is 'John + run'), and in clause[s] with resultative elements (Attribute, Rôle) such as I'll boil the eggs hard (outcome: 'eggs + be + hard'), Let's appoint Fred timekeeper (outcome: 'Fred + be + timekeeper').