### Pull-Push Strategies and Systems  
Pull and Push strategies are the basic production and logistics strategies described by some authors as 'functional', that is, according to the classical classification, they are at the lowest level, below competitive strategies, above which are global strategies [1]. At this level, another \"functional\" strategy is defined--the size of the distribution network (strategy of centralizing or decentralizing the warehouse network). The choice between different strategies is a decision-making problem that should be solved based on a cost-effectiveness calculation. Strategies at all levels should be consistent with each other, i.e., the strategy at a lower level should stem from the strategy at a higher level. Thus, it seems that the choice of a competitiveness strategy (competing on price or quality) determines the choice of a production or logistics strategy. However, a given production or logistics strategy does  
Figure 1: Pull and Push strategies at different stages of a production–logistics chain. Source: own study. not always result in lower costs or better quality. Therefore, it is necessary to carry out calculations to assess the effectiveness of a given strategy. On the stage of the production process, the strategy \"Push\" is defined as \"Make To Stock\" (MTS) and the strategy \"Push\" is defined as \"Make To Order\" (MTO) [2; 3]. These strategies have an impact both on the costs (production, logistics) and the level of logistics customer service. That means that they can indirectly impact the level of sales (Figure 2). The choice of a given strategy has an impact both on the level of inventories, the capacity for production, the logistics potential, and the technology used (mechanical, automated). They also influence the flow of goods in physical distribution--if the products will be \"Pushed\" or \"Pulled\" by the distribution field or directly by customers. MTS and MTO are two strategies that can be applied in different markets, for different customers and different products. The efficiency of a given production strategy with changing customer requirements depends, among other things, on product characteristics [4]. So, it is not always necessary (and possible) to compare them. The choice of a particular strategy can be influenced by the characteristics of demand (volume of demand, predictability, volatility), the length of lead times, and the nature of cooperation in supply chains [5]. MTO can be chosen for low-volume products, with a wide assortment and low unit volume, manufactured according to individual customer orders. MTS can be used in mass, repetitive production, for high-volume and standard products with a predefined and narrow assortment [2]. In addition to customer demand characteristics, there are also other conditions for the successful implementation of these strategies. In the case of MTO, this condition is a high degree of integration with the suppliers of production materials [6]. There can be combinations and modifications of MTO and MTS strategies. The strategies that combine their advantages are \"Postponement\" or \"Assembly To Order\" (ATO). In practice, managers of manufacturing companies usually employ more than one strategy [7]. This includes Engineer-to-Order (ETO). \"ETO firms\" produce complex, \"one of a kind products\" and desire shorter lead times as a key factor of the cost competitiveness. Unlike other manufacturing models such as MTO or MTS, the design for an ETO product is not realized until after the engineering process has been completed. Therefore, the problem becomes the determination of an accurate schedule within a complex transactional process for jobs, which have not even been designed yet [8]. For Engineer- and Design-To-Order (ETO and DTO) industrial environments, proper tools are needed. These include, for example, Plan For Every Order (PFEO), which collects information on both suppliers and materials, improving both the management of materials and spaces and communication between the company and suppliers [9].