Draw the triangle above and ask which elements are fixed and which are flexible. Explain that a restriction on one aspect on the triangle, e.g. cost, will have an impact on the other two; time and scope. During this conversation, try to establish what design package might fit this model (UX, Service Design or Transformation) based on their business case, budget and timescales.
Is there a budget for the work? If there is, how has this been calculated?
Is the budget an estimate based on a business case, or is it simply that there is only so much money that can be released for the project?
Is there a business case for what your customer wants to achieve? The business case should detail the problems they are trying to solve and the potential value of solving them.
What are the problems with the existing service or situation? Capture as many of these as possible, but make sure you prioritise them to the top 3. If these 3 problems were solved, would the customer be happy?
Is there a deadline for when the service is needed? If there is, find out if this is a real deadline. It could be that a licence is about to expire or some software is going out of date.
However, people will often attach made-up deadlines to boost priority. This can be quite harmful, as an unreasonable deadline could mean the work does not get completed, or is rushed to an inferior standard.
Ask why the deadline is in place and if there is any flexibility.