Lean Manufacturing and MRP to speed up the steel structures manufacturing in the construction industry

The construction industry is one of the most demanded sectors in Peru and this is shown in its contribution to the national GDP, which since 2017 has kept a constant growth o f no less than 4%, however, one of the problems that constantly complains about are the late projects delivery. It was found tha t 67% of Peruvian construction companies deliver their works out of date. Indeed, the lack of specialization of the companies that overflow in a country with low rates of formality such as Peru. This leads to internal problems that eventually end up delaying the projects delivery. By comparisons of the sector, it has been found that the common delay of the most successful companies in the sector does not exceed 11 days, a situation that is not reflected in most construction companies that are mostly small or medium-sized companies with almost no ignorance of useful tools that engineering has to offer. The case study evaluated in this research, The company Yañac SAC, is a construction company dedicated to several services among which is the assembly of steel structures for construction such as beams and columns. The main problem in this company is the lateness in projects delivery, which cost reaches to s/127, 405.39 and, to face this, the Lean Manufacturing methodology and its tools are applied in combination with MRP to reduce the impact of the problem. Finally, as a result of the simulation, it was possible to achieve a model within the error of 5% with respect to the real production and applying the improvements in the productive times from the investigation of scientific articles an improvement of 22% was found with respect to the initial scenario, managing to execute 459 production requests for beams and columns per month. From the economic validation, a NPV greater than 0, an internal rate of return (IRR) greater than the COK and a cost benefit ratio greater than 1 were determined, which indicates the project is profitable. Similarly, a low level of social and environmental impact was determined, so it is concluded that the project is viable in these two aspects.