Who is going to implement the components of the voice response service? Is the department who understands the business and the callers going to develop the application themselves? Or do you have professional programmers or a service bureau that you can call upon? Even if you use professional programmers or a service bureau, the business departments and the callers themselves should be involved too. Conversely, even if the business departments are comfortable with implementing small and medium-scale systems, it may be advisable to involve system integrators if you are scaling up to something large.