The popular 'SMART’ framework can be used to ensure that all objectives are well thought through.

SPECIFIC
Articulate what the outcome should be, why the objective has been set and how it will be achieved.
 
MEASURABLE
Clarify how performance in relation to the objective will be assessed. Specify a number, percentage or value, or define how feedback will be obtained.
 
ACHIEVABLE
To be motivating, objectives should be challenging but realistic, given the resources available. According to productivity guru David Allen, objectives should be '51% achievable’ - highly challenging yet just about attainable. Tough but achievable targets fire people’s competitive instincts.
 
RELEVANT
Objectives need to relate to the unit’s or whole company’s targets, and to the person’s individual responsibilities.
 
TIME-BOUND
Specify the timeline for completing the objective and, whenever possible, key milestones along the way so progress can be reviewed at appropriate times.
 
Objectives are typically set annually, and incremental progress towards them reviewed regularly. At the end of the year, the manager and employee usually meet to appraise how well the objectives have been met and to set fresh objectives for the year ahead. Appraisals should be conducted in a relaxed, informal, unhurried atmosphere. Set aside 60-90 minutes for the meeting and chose somewhere suitable for a private conversation. Most companies will have a formally prescribed process for annual employee appraisals, carefully vetted from an HR and business strategy standpoint. The conversation is generally managed along these lines:
 
BEFORE MEETING
- Employee and manager each assesses achievement versus objectives
- As part of this, manager collects data, evidence, feedback from others and specific examples to form a point of view
- Manager considers what next year’s objectives might look like

DURING MEETING
- Employee shares their assessments
- Manager highlights any differences of opinion, and then listens (see Section 2.3)
- Manager refers to data, evidence, feedback and examples as necessary
- Employee talks about longer-term career aspirations
- Both discuss new knowledge and skills required, and ways they could be developed
- Manager shares thoughts on following year’s objectives, adapted per the discussion
- Both discuss and agree on objectives and accompanying learning plan

AFTER MEETING
- Manager writes up what was agreed to, making objectives SMART(er) if necessary
- Employee checks the write-up, adds their comments if desired, and signs a document acknowledging the performance appraisal and forward-looking objectives

See also 'Identifying Balanced Objectives'.