It’s a chicken-and-egg thing: an indicative budget is not a decision about the final budget or the care plan. But a council will always want to be fair to people and thus a consensus is inevitable about roughly what a package of care for a person of a particular profile of needs is likely to cost. And that’s a starting point for discussion, as long as the starting point is not a completely arbitrary one!
So the theory is that the issues/difficulties that have been identified by assessment should be translated with expertise and professional judgment about what works and what exists, and combined with input from the person and/or their family or advocate as to the most important aspects of how care is to be delivered, for the person in question, INTO a set of inputs – services, hours, activities etc – and then those go into the care plan and the budget is the sum needed, in the real world (the local market), to cover these inputs, so that outcomes that matter to the person in question are able to be reliably met.
The council is not obliged to meet the needs in the best way possible, but only in a way and to an extent required by the statutory purpose, which is to reduce the impact of the person’s difficulties on their wellbeing, down to something less than ‘significant’ both objectively, but also taking the person’s own wishes and feelings and what matters most to them, into account.