# Designing of Machine Backups in Reconfigurable Manufacturing Systems
## 2 Materials and Methods  
Designing reconfigurable manufacturing lines is a complex solution and consists of various modules (see Figure 2). Figure 2 shows the module Product family creation, in red, which is described in detail in the present article. The modules from Figure 2 were characterized in detail in the study: the design of manufacturing lines using the principle of reconfigurability [26]. Therefore, only a brief description of their function and purpose concerning the overall methodology is given. This study [26] deals with a general description of the proposed calculation model. Still, it does not detail the principles for calculating equipment advances for this methodology, nor the product family creation process and simulation. At the end of the article is the nomenclature of all variables used. After defining specific parameters in the input data procedure module, the algorithm of the proposed methodology verifies the feasibility of the defined operations from the time and operational point of view (module capacity and operational availability). If the products meet the specified conditions, the validation of product manufacturability in time procedure is continued. This module defines the criterion of the minimum time required to produce each product. The sequence of assigning products to a product family is further defined using this data. The assignment sequence is defined by the Short Processing Time criteria and the Cluster analysis results. Subsequently, product families are created, and the required backup is calculated for each new product family. After defining the backup and the specific number of machines, the product family products are produced until the end of manufacturing one of the family products. This is followed by another iteration of creating a new product family, thus re-determining the number of machines and the required backups. Professor [PERSON] defined six core RMS characteristics [27]:  
* Scalability (Design for capacity changes)--The capability of modifying production capacity by adding or removing resources and/or changing system components;
* Convertibility (Design for functionality changes)--The capability of transforming the functionality of existing systems and machines to fit new production requirements;
* Diagnosability (Design for easy diagnostics)--The capability of real-time monitoring the product quality, and rapidly diagnosing the root causes of product defects;
* Customization (Flexibility limited to part family)--System or machine flexibility around a part family, obtaining thereby customized flexibility within the part family;
* Modularity (Modular components)--The compartmentalization of operational functions into units that can be manipulated between alternative production schemes;
* Integrability (Interfaces for rapid integration)--The capability of integrating modules rapidly and precisely by hardware and software interfaces. Our articles primary deals with fourth point--Customization. But in complex way, we must solve all six core characteristics. So, the article deals more with the product family creation module, which consists of three main parts. This module must prepare the necessary data and sources before the design solution (Section 3). The first part is the creation of a product family cluster (\(\alpha\)) and determining the production volume for the defined operations of the production configuration. The second part is recalculating the required number of machines (\(q_{\alpha}\)) for the proposed configuration and its subsequent verification utilizing simulation software. The third part specifies the required device backup for a verified configuration containing two or more products. The products are assigned sequentially depending on the proposed overall assignment sequence and the number of unassigned system devices.