Goals play significant role in decision making. Most organizations can be assumed to set and then pursue certain goals either stated explicitly or assumed implicitly. In realistic models, the goal is not a constant but a variable: it can erode due to persistent failure or it can evolve further as a result of confidence caused by success With respect to many different types of goal dynamics, there exist some models of limited and linear goal erosion dynamics in the literature. We extend the existing models to obtain a comprehensive model of goal dynamics, by including organizational capacity limits on performance improvement rate, performance decay when there is no effort, time constraints and pressures, motivation and frustration effects. The model constitutes a general theory of goal dynamics in organizations. Our model also demonstrates some strategies to avoid the undesirable goal and performance erosion in various unfavorable, risky goal seeking environments.