Structured decision: there is a standard way of getting to a correct answer. For example: Should we authorise a customer’s order? Answer: authorise provided the customer stays within the credit limit and is not behind with payments.
Unstructured decision: no standard way to get to a correct answer. For example: how many units will we sell next year? Answer: it depends on all sorts of influences – the economy, competition, how much we spend on advertising. There is no way of correctly predicting sales.