Integrating two stages of Malmquist index and Grey forecasting to access industrial performance: A case of Vietnamese steel industry

Vietnam's steel industry is in its developing stage with significant progress since the openness of the economy. Many companies in this industry have adopted the development and advancement of technologies used in manufacturing. However, the productivity of the steel industry in Vietnam is still considered low compared to other countries, which leads to the decline in competitiveness in terms of Vietnam steel products to its competitors. Companies in the steel industry, as well as the government, need to know about productivity and performance in order to give out vital decisions for the development of the steel industry which is one of the prior and core industries in Vietnam. Thus, evaluation of the Vietnamese steel industry has become a significant issue. This study takes advantage of the integrated Data Envelopment Analysis model and Malmquist Productivity Index to evaluate the past-to-future performance of the Vietnam steel industry in two different timeframes; the first period was from 2014 to 2018, the second is from 2019 to 2023, which are the results from Grey system forecasting. Totally, the realistic financial reports of 16 companies are considered to be in this evaluation after the strict selection from the whole industry. Three factors are put into consideration, including efficiency change (catch-up), technical change (frontier-shift), and Malmquist productivity index are examined respectively, in each period mentioned. The results find that the performances of all companies have not shown many abrupt changes on their scores except some outstanding cases, which demonstrate the high applicable usability of the integrated methods.