LIKO Vrhnika d.d., PE Doors is a factory producing doors and frames. Due to more and more demanding buyers and strong competition on the market, it is forced to develop new products and adequately present them on the market. The practical course of development of new interior doors named PIANO is presented. Two stages of the development process are analysed: technology and manufacturing, and the market development of new products. The analysis of the findings shows deviations from the development of a new product in theoretical 8 stages. The development of a new product is a positive experience for the factory because it confirms that effective teamwork can produce positive results despite skipping some stages of the development.