Many of software projects are technically driven in nature. That includes the users mindset where the software will solve daily issues. That is half correct because software is usually built with best practices from known industry SOP (standard operating procedures). Thus, we tend to ignore the existing process that will be impacted by the new system. Customisation and change management are common reactions when you bring your own process into the software projects.

Customising
Customisation is the most common approach taken when evaluating the current business process. Change is resistance and the demand to customise will echo in major projects. It is known that you should limit customisation to less than 20%. If you are facing more than that, it means that the software product you have is not a good fit and you are better off doing turnkey development.
Change Your Process
The fear of change is major factor towards project failures. If getting top notch software products is the key reason, it is worth considering change management for existing SOP. It also makes no economical sense to customise process by each office. The driver to change management is usually triggered by cost reduction and operational efficiency.
The strategy for new software implemented must be done with the understanding of existing processes. Often, this is neglected during the pre project phase. The approaches in your project will be either a mix of customisation and change management to leverage on the features and conforming to local business processes.