A comparative study of more effective vs less effective planning systems is reported here, where effectiveness is treated in terms of the fulfillment of six key planning objectives. Based on data on the strategic planning systems and processes of over 200 North American companies, key systems design and contextual factors associated with effective planning are identified. It was found that dissatisfaction with formal strategic planning is not as widespread among practicing managers as is widely alleged. The degree of fulfillment of key planning objectives varies widely not only from company to company but also from objective to objective. Overall, the creativity and control orientation of the system and its level of functional integration were found to be the principal design factors contributing to the effectiveness of a strategic planning system.