Optimization of activities of road construction company based on lean manufacturing tools

The article proposes an algorithm for implementation of lean manufacturing in relation to a company in the road construction industry. The concept of lean manufacturing involves the possibility of using several tools at the same time to solve the problems and losses encountered during construction and installation works. The results of testing a tool such as a 5S system in a road construction company are presented to confirm simplicity and effectiveness of the proposed recommendations.


Introduction
In modern conditions of economic development, enterprises of various industries are constantly forced to adapt and improve business organization. So, the management of large Russian companies often makes the decision to apply the principles of lean production in order to increase the efficiency of production activities. As a rule, it happens due to the active dissemination of information about the successful experience of European and American companies in various industries in the implementation of individual lean manufacturing tools.
Large industrial companies such as Russian Railways OJSC, Sberbank PJSC, KAMAZ PJSC, Rosatom State Corporation and many others also have experience in implementing this concept in Russia.
However, despite the real results of the concept, such as increased labor productivity, improved product quality, reduced rejects and production time, many top managers emphasize the difficulties encountered in its implementation. In most cases, these difficulties were caused by a number of problems, such as: low staff involvement, making mistakes in instructions and regulatory documents, technical impossibility of using concept tools in the production process. At the same time, it must be emphasized that many companies, when introducing and once using the tools of the lean manufacturing concept, without receiving a visible positive effect and quick results, subsequently return to the original version of the established production process.
In order to optimize the activities of road construction industry companies on the basis of lean manufacturing tools, an analysis of a number of domestic and foreign sources was carried out to identify the features of the use of concept tools in Russian practice and the reasons for abandoning it.
Despite the fairly widespread practical implementation of the concept in domestic and foreign companies, there is no mention of positive experience of using the concept tools at the enterprise of the road construction industry as one of the most material-intensive and costly in the world.
In this regard, the need has arisen for a theoretical and applied study of lean manufacturing as the basis for optimizing the activities of a road construction company.

Methods
When creating an algorithm for implementing the concept of lean manufacturing, it is important to identify the main production problems that a road construction company faces, including following: 1) large volumes of consignments of material resources that are stored in an open and closed way; 2) insufficient loading of specialized equipment, which is most often associated with the seasonality of work performed and frequent repairs; 3) significant number of movements and transportation; 4) insufficient staff load; 5) high flow time of individual business processes. Specific production problems of a road construction company can be solved with a separate tool or a set of lean manufacturing tools, the main ones being distinguished ( Figure  1): standardization of work; organization of workspace (5S); -Value Stream Mapping (VSM); visualization; single-minute exchange of dies (SMED); protection against unintentional errors (poka-yoke); prevention of occurrence of unintentional errors and their prompt elimination until the operation is stopped, so that the inappropriate part does not fall onto the next; structured information system that regulates the processes of supplying production and supplying the desired volume of products to the consumer (Kanban); total productive maintenance (TPM). When implementing lean manufacturing, the initial step is to identify production problems and types of losses using mapping. Mapping is used as a tool for visualization and analysis of material and information flows in the process of creating value from a supplier to a consumer. At the same time, production losses can be detected only in one way -by going step by step along the production site all the way from the order to the delivery of the road construction object. In this process, all employees of the company who in any way affect the efficiency of this stream should be involved.
The whole algorithm for implementing lean production in a road construction company is presented in Figure 2. The proposed algorithm for the implementation of lean manufacturing in a road construction company is based on the assumption that one of the key environmental factors affecting the level of competitiveness of a company in the road construction industry is the duration of construction and installation works. In this regard, when determining problems and production losses, it is important to take into account the dependence of this factor on the duration of public procurement process cycles, as well as pre-project and project work.

Results
In order to test the proposed recommendations, current parameters of the production process were assessed and problems of production activities were mapped in the road construction company DRSU-1 TODEP JSC, which carries out construction and installation works in the Tyumen region.
Mechanical repair workshop of the enterprise (MRW), which has several sections on its territory: a tire fitting section, a locksmith section, an electrical section, was chosen as a reference section.
The list of identified problems in the reference area "repair and mechanical workshop" is presented in table 1. When repairing equipment, the working tool is scattered on the floor, which leads to its loss, pollution, as well as to an increase in the complexity of work 12 The entire working tool is scattered around the site, which leads to unnecessary movements of workers In case of an emergency stop of special equipment at the site of construction and installation works and maintenance of roads, there is a long and uncontrolled (in quality) repair to replace damaged consumables, which leads to downtime of the entire production process (construction and installation work), idle speed of special. equipment to MRW (maintenance of roads) and an increase in the volume of work when special equipment leaves the line 23 There is no daily inspection of special equipment in the winter, which leads to an emergency exit of special equipment on the line 24 No technical inspection of special equipment located on the construction and installation works to prevent emergency stop Losses identified during the assessment of the current state, such as waiting, excess traffic, defects, it was decided to exclude using the system of rational organization of the workplace 5S. This system assumes the presence of following elements: 1) "sort", i.e. distribution of objects of labor in the workplace by degree of suitability; 2) "set in order"; 3) "shine"; 4) "standardize"; 5) "sustain" i.e. improvement and formation of industrial culture. In this regard, an algorithm for step-by-step implementation of the 5S system was formed on the reference section "mechanical repair workshop" DRSU-1 of TODEP JSC: 2. Visualize the rules of maintaining the workplace, the storage location of the tool, the material used, according to the 5S standards; 3. Standardize and unify all designations (size, color, image of symbols, etc.); 4. Conduct an audit, after implementation of the stages of "Shine" and "Standardize". Stage 5 (Sustain): to develop and implement audit procedures for the organization of the warehouse facilities in accordance with the principle of the 5S system.
Together with the 5S workspace organization system, such a lean manufacturing tool as visualization was used. This tool allows to clearly analyze the current state of production processes, reduces the risk of injuries in the workplace, and proper marking reduces the time spent on searches and reduces the number of defects.
For visualization of information, marking, stands, marking and information boards are used.
The action plan to address the identified problems in the reference area "repair and mechanical workshop" is presented in table 2. To implement and control the implementation of lean production in the road-building company DRSU-1 of JSC TODEP, a schedule was drawn up taking into account the timing of activities and assigned responsible persons (table 3).

Conclusions
Practical use of the 5S lean manufacturing tool and the accompanying visualization tool allowed us to achieve following results in the construction and installation works of the company: -increasing labor productivity and overall performance; -reduction of losses of working time; -lower costs; -reducing the duration of cycles of construction and installation works; -reducing training and maintenance of specialized equipment. Also during the survey, company employees noted positive results after the implementation of measures such as: reduced fatigue, reduced injuries at the workplace, increased job satisfaction, and creation of a safe and convenient workplace.
However, it should be noted that the use of lean manufacturing tools requires constant monitoring of the effectiveness of measures and improvement. At the same time, it is important to promptly fix the ongoing changes through updating current standards.