Emmanuel - Consultant
The short answer is ‘with difficulty’. Think about the strength of your existing relationship, the significance of the goods or services being supplied – would there be negative consequences if you apply more pressure? – and their complexity. This informs not only the tactics but also the vigour with which negotiations can be pursued.
The need to be informed is never truer than when dealing with a monopoly supplier. As well as your contract,, you should have a knowledge of market trends, any bad press and reports on the supplier’s financial performance.
If prices are inflexible, identify where improvements to the service will provide most benefit that won’t impact costs. These are often easy for the supplier to offer and enable it to test out services it wants to develop. If you are unconcerned with making the relationship worse, a further option is to attack the supplier’s value chain, identifying costs that relate to a part of their service which you do not recognise as valuable. But beware the dangers of this.