SMART is a management methodology in some part based on management by objectives set out by business guru Peter Drucker.

Specific  – Be specific not vague. What are you setting out to achieve
Measurable – Can it be measured. Not just the ultimate goal but also the steps towards the objective

Achievable – Are your goals reasonable. This has implications for both under-achievement and over achievement. Also consider what constraints you may be operating under.

Realistic – usually set in the context of whether you are the right person to do this.