In the era of widespread adoption of information technology, increased flow of information around us and a dynamic lifestyle – all those impose critical and rational approach to planning activities. Fast and clear development and implementation of effective decision making becomes the key to successful activities and achievement of the organisational goals. Taking in consideration large amounts of incoming and processed information, it becomes important swift and efficient selection of information, its distribution into categories, and assessment of its reliability. One of the main challenges in planning is how to overcome the vast amount of information, unknown, and ignorance, at the same time, elaborating plan at an acceptable level. The purpose of this article is to explore how fast and reliable decision making is possible in planning. The planner is partially aware of past and present situation. Theoretically grounded and experimentally confirmed knowledge, by definition, are always in the past. Knowledge is never in the future. The focus of planning is on developing a plan that is applicable for the future. Partial knowledge, adaptive approach and approximate predictions about future situations are always not enough for decision making. The planning paradox is that the action plan is placed in the future, and there is no yet experimentally proven knowledge in the planned future. However, planners manage situations through decision making. Therefore, fast and, at the same time, optimal and high-quality development and the implementation of the decision is of fundamental importance from planners’ point of view to achieve organizational goals with a practical degree of reliability in the face of uncertainty of knowledge, task completion and time pressure.