The paper deals with the problems of material ordering business process quantification with the use of linguistic sets, the behaviour of which is regulated by the principle business processes linguistic equation – PBPL. The purpose of this paper is to design an optimal architecture model of the abovementioned business processes related to their structure, features and functionality. In order to fulfil the main task, several objectives should be postulated and achieved. The first objective is closely related to the analysis of the material management business process, the aim of which is to describe the structure of that business process (BP) and principles of its functionality with regard to optimisation of appropriate BP metrics. The second objective is to design an optimal BP model, an integral part of which should be a description of principle aspects related to the implementation of the optimal model. The author has provided information dealing with the application of the PBPL equation in analysis and design of the material ordering business process, which constitutes an integral part of production material requirements. The described structure represents a qualitative proposal, which forms the basis for the development of materials management business processes in terms of design and optimisation. The research was conducted at RM GASTRO, a group manufacturing joint-stock companies with a number of employees equal to 1,000, in June, 2015.