<p>This paper investigates how the cognitive proximity created by ICT and Industry 4.0 influences diversification strategies in manufacturing. Our analysis is carried out in two stages: stage one comprises a theoretical reflection from the viewpoint of the evolutionary theory of technological development, and stage two presents results from empirical studies available concerning diversification processes in the manufacturing industry. The paper suggests that specialist production strategies outperform diversification strategies, which are difficult to implement. That difficulty can be explained by the fact that a scenario conducive to diversification strategies requires the business that wishes to diversify to be large, to have a high innovation capacity and to work in a product field that uses technical solutions with a low level of combinatorial complexity. Failure to meet any one of these three requirements (i.e. if the business is too small, not capable of sufficient innovation or seeking to diversify in product fields with high combinatorial complexity) is an obstacle to diversification. Logically, the availability of a setting in which the necessary technology resources are available also facilitates the setting up of diversification strategies.</p>