This article written from perspective of a person from technical or IT department. Can be developer, analyst or even manager.
Why a person from technical team should build good work relationship with high management or business team?
Understand the Business Better
By doing so the technical team get chance to know the business process and pain points and come up with more attractive solution for business.
IT or technical team usually seen as cost-centre. Now can be an indirect revenue center, creating value by understanding the business. Create tools/process/application/solution which create big value for overall business operations even have changes reduce more cost or even open doors to create new revenue streams.
Cross Demand Interest Management
Business team usually have upper hand when comes a project. Existing relationship helps manage the expectation, manage any conflict, or get middle ground whenever a discussion happens. A friend-like relation will allow the other side team support you indirectly or even let the guard down.
In most companies, project budgets are still under business/finance teams P&L. The situation is changing fast, but this is still the common scene.
When you come up with a brilliant idea for business to benefit, you have to cross seven seas seven mountains explaining and convincing to secure the budget. You still have to do all the justification, but with the pre-built trust with business/finance teams, make the hike much more easier.