Self-management could be limited to controlling how work is done, or it could entail control over capital investment, prices, and output. To my way of thinking, the former is a pretty pale approximation of "Workers' control." You could stipulate that workers may not sell their plant's capital -- only buy it. This also would put quite a crimp in workers' control, as well as in ANY concept of economic efficiency.
If we agree that the Hahnel-Albert set-up, which I do not claim to know much about, generates a "plan," then I guess we could say that some workers' control is compatible with certain types of "planning." So we can solve the problem by definition in either direction.
Certainly firms in markets do not operate without constraints imposed by the market, as well as other institutions. The question would seem to be, what conditions on its operations, by virtue of the HA democratic process, become binding on the firm, and in light of those constraints, can we conclude that the workers have control or something less than that.
Self-management is an appealing alternative to what I would call welfarism, and certainly compares well to commandism. The consistency of an anarchist critique of states in general is salient as well. But I would say the market, with its likely disadvantages, is an inevitable feature of these alternatives, on which can only be offset by a state, if not a plan.
, which I do not claim to know much about, but that's a different issue. Under HA, to the best of my knowledge, final decisions are not left to workers in their capacity as members of a particular enterprise. Their interests are somehow reconciled with those of consumers without benefit of markets.
BL seems to argue by assertion, saying my distinction is just wrong. Could be true, but why is still beyond me.
Under real workers' control, you would have rich enterprises and poor ones, hence some inequality. But 'socialization of the market' is the only practical road I see to socialism. I'd expect less inequality, and more scope for welfare state alleviations of the effects of inequality.