This study examined the effectiveness of strategic planning systems in strategy formulation in a changing business environment. It also investigated differences in the designs, processes, levels of top management involvement, and perceived levels of achievement and performance of the strategic planning systems of companies classified as leaders, challengers, followers, and nichers in the electronic computing equipment community. For the most part no significant correlations were found between perceived levels of achievement and performance of planning systems and organizational performance measured by financial ratios. However, significant correlations were found between perceived level of achievement and performance and the design, process and level of top management involvement in the strategic planning process.