More general:
* Goals
* Targets
* Aims
* Objectives
* Aspirations
* Desired outcomes
* Key performance indicators (KPIs)
* Performance standards
* Expectations
* Benchmarks
More specific:
* Business objectives: Business goals, strategic objectives, key result areas (KRAs)
* Individual objectives: Personal goals, individual targets, development goals
* Project objectives: Project goals, project deliverables, project milestones
* Team objectives: Team goals, team targets, team performance indicators
More informal:
* What you're trying to achieve
* What you're aiming for
* What you want to accomplish
The best synonym for "performance objectives" will depend on the specific context and the desired level of formality.