The Specific Features of design and process engineering in branch of industrial enterprise

Production output of industrial enterprise is organized in debugged working mechanisms at each stage of product’s life cycle from initial design documentation to product and finishing it with utilization. The topic of article is mathematical model of the system design and process engineering in branch of the industrial enterprise, statistical processing of estimated implementation results of developed mathematical model in branch, and demonstration of advantages at application at this enterprise. During the creation of model a data flow about driving of information, orders, details and modules in branch of enterprise groups of divisions were classified. Proceeding from the analysis of divisions activity, a data flow, details and documents the state graph of design and process engineering was constructed, transitions were described and coefficients are appropriated. To each condition of system of the constructed state graph the corresponding limiting state probabilities were defined, and also Kolmogorov’s equations are worked out. When integration of sets of equations of Kolmogorov the state probability of system activity the specified divisions and production as function of time in each instant is defined. On the basis of developed mathematical model of uniform system of designing and process engineering and manufacture, and a state graph by authors statistical processing the application of mathematical model results was carried out, and also advantage at application at this enterprise is shown. Researches on studying of loading services probability of branch and third-party contractors (the orders received from branch within a month) were conducted. The developed mathematical model of system design and process engineering and manufacture can be applied to definition of activity state probability of divisions and manufacture as function of time in each instant that will allow to keep account of loading of performance of work in branches of the enterprise.


Introduction
Production output at the industrial enterprise means the debugged working mechanisms at each stage of the product's life cycle: from initial design documentation for the product (depending on a sort of the workthe preliminary design, the engineering design, development of working design documentation, further DD) [1], and finishing it with utilization. In the part of development and preparation of production of products this refers to uniform system of designing and technological preparation of production (DTPP). It's considered processes of design, design-preparation, engineering studies, preparation of documentation (design, technological, program) for production and directly production.

Problem definition
The work of territorially remote branch which is in other city is carried out by means of connection to informational resources and databases of head plant through the protected Internet channel. At the same time licenses for operating system, office programs, and CAD-systems, take also via the Internet. The branch carries out development of DD and manufacture of a prototype of a product with the subsequent small-scale and serial production. In this regard technological preparation of production passes on the second plan, however in the long term at expansion of private production base these works will be performed (proceeding from technological equipment of branch and optimization of production). Development of DD is conducted in CAD-system the Kompas. For elements, necessary to application (reference products, materials) requests for adding in databases and reference books are made out, and business processes in the PDM-system Lotsman are started. Generally the scheme of processes of design and technological preparation of production has the appearance presented in fig. 1. In branch of the enterprise in the conditions of original lack of equipment, the mastered technology and licenses for CAD/CAM/CAE systems [2] the scheme of processes of design preparation is submitted in fig. 2. he principle of action according to the scheme of processes consists in work in PDM-system with an array of the corporate reference books (directory system, reference products, materials and ranges) and the ESKD qualifier). The main theme of the article is development of mathematical model of system of design and technological preparation and production in branch of the industrial enterprise, and also statistical processing of estimated results of application of the developed mathematical model in branch, and demonstration of its advantages at application at this plant.

Theory
The mathematical model of the DTPP system at ару branch is under construction on the basis of theory of probability postulates, in particular, of the theory of a queuing and mathematical statistics [4]. The random process which proceeds in system S is considered as Markov if it proceeds without after- It is possible to define probabilities of states by the marked state graph as functions of time. These probabilities satisfy to Kolmogorov's equations. In these differential equations probabilities of states will be unknown functions. Therefore, having solved these equations, it is possible to calculate probabilities of conditions of production as functions of time. We will take a route list on printed circuit boards, details and clusters for unit of fluency of events λ which switches the services from state Today in branch the technology of a turn of route lists is not functioning yet. The engineering service is presented by one design-technology department, blanking shopsby third-party contractor, and assembly shopsby one assembly site. In this regard the offered classification of groups for branch is represented in fig. 3.

Design and Technological Department (DTD).
This department is performed design preparation of production and technological study of products. This activity is not performed yet.

Results of experiments
On the basis of monitoring of activity of the divisions involved in production process, authors investigated loading and rhythm of work of services of branch in the course of manufacture of a standard product. Coefficients according to transitions of a state graph of design and technological preparation of production and production were experimentally calculated. For averaging of indexes basic accepted the beginning, the middle and the end of month. Results of researches are given in the Tab. I.  Using the calculated coefficients in equation system (5-7) taking into account that at constant probabilities their derivants are equal 0, and also applying a normalizing condition (8):    In the course of the analysis of the developed mathematical model, and application of the explained methods and the principles, authors were it is offered to make essential changes to the current business processes of design and technological preparation and production of the enterprise. These changes led to the larger transparence of production consisting in expeditious emergence of actual information about the course of production process to chiefs of divisions of all ranks and persons, responsible for a condition of production, and also to reduction of time and decrease of probability of inaccurate information transfer, details and blocks. It, in turn, positively affected dynamics of implementation of the production schedule, and also prime cost of products. In general, it depend, including, from padding expenses, the bound to losses of time and financial resources on elimination of consequences from irregularly or not in time the made decisions and actions of personnel.
Thereby, proceeding from results of the conducted researches, it becomes apparent that application of the developed DTPP mathematical model and production allows to increase in general loading of services that increases rhythm of their work and, as a result, labor productivity.

Discussion of results
From data of research it is visible that probability of loading DTD within a month is step by step increases (from 0.0033 to 0.0065). The probability of loading of the third-party contractormanufacturer of details (Mech) increases during the month from 0.0802 to 0.1035. The probability of loading of the third-party contractor of galvano-paintings (GP) within a month from value 0.2090 increases to 0.2277. The probability of loading of an assembly site from value 0.7075 decreases to the end of month to 0.6623.

Summary and conclusions
The developed mathematical model of system of design and technological preparation and production can be applied to definition of state probabilities of activity of divisions and production as function of time in each instant that will allow to keep account of loading of performance of work in branches of the plant.