This paper employs a method of holistic thinking to see which of the twenty plus internal factors empirically identified in the literature are primary forces underlying the innovativeness of a manufacturing firm and which ones are secondary or appear naturally after the primary forces are created. Based on how organizational culture is formed in general, the effects of firms’ culture on innovation are analyzed. By using a general cost-benefit analysis, the effects of firms’ general characteristics on innovation are studied. Though modelling a firm systemically, the effects of firms’ structure on innovation are seen clearly. With the concept of leaders well explained, the effects of firms’ leadership on innovation are shown.  At the end, practically useful recommendations for managerial decision making are provided.