In the machine building industry, both the choosing products and their life are uncertainly, because the diversity of the machines models and equipment and faster and faster changes of the customer wishes prevents any prediction of demand. Thus, the production of the machines must adapt to the actual demand of each buyer and to have the flexibility for this goal, under acceptable economic conditions. The first part of this article was dedicated for defining the concept of flexibility and the connection between this and other concepts, then I tried to point out that under the increasing pressures of the consumers that request increased quality, a faster development of the product and better post-selling services, the companies are forced to adopt a high strategic flexibility, to which contributes all functions of the production systems.