This chapter explores how companies—particularly small and medium-sized enterprises (SMEs)—differ in their innovation approaches, ranging from structured models to flexible, ad hoc methods. While some studies suggest that larger firms achieve higher innovation performance, others find no consistent relationship between firm size and innovation success. The chapter highlights SMEs’ strengths in agility and responsiveness but also notes challenges such as informal communication and process inefficiencies. To address these issues, Cooper’s Stage-Gate Model is presented as a structured framework that standardizes innovation processes through sequential stages and decision gates. This model enhances transparency, coordination, and control in innovation activities. The chapter concludes that innovation success depends less on company size than on finding the right balance between structure and flexibility. This discussion provides the foundation for examining closed and open innovation approaches in the subsequent chapter.