There are many aspects to consider when setting goals. As it is almost always abandoned before it is completed, creating the right mind set and rules to follow would be a good. This is one way to ensure the percentage of abandonment is decreased.
Initially at its conceptual stage there may be some unrealistic expectations placed on the group or individual with regard to achieving the goal. It is not unusual to have to address these minor hiccups and rethink the schedules pertaining to the efficiency of completing the goal.
Several factors need to be considered when dealing with time lines. If the goal is to be reached as a group then the complexities involved are doubled if not tripled.
The commitment of each person must be without any doubt, if the group is to function effectively. If the goal accomplishment only involves the commitment of one individual, the commitment level does not necessarily change that much. Ensuring the element of procrastination is never present is very important.
After being assured of the level of commitment of each person, drawing up specific time frames is prudent. At every juncture, there should be a check on the progress and performance toward reaching the goal.
If any discrepancies are found, it should be addressed immediately, and a further deadline should be set, to address this particular problem, without effecting the overall time line drawn at the beginning.
Ideally there should be a very comfortable stop gap period which leaves everyone fully able to complete the intended task and reaching the goal with time to spare. These allowances are extremely important to counter any unforeseen problems. When time lines are strictly kept, the confidence levels of all those involved also grows and the results are better qualities shown in the quest to reach the goal.