###### Abstract  
The smartphone is a must-have mobile device for the military forces to accomplish critical missions and protect critical infrastructures. This paper explores the applicability of a technology prediction methodology to manage technological obsolescence while pursuing the acquisition of advanced commercial technology for military use. It reviews the Technology Forecasting using Data Envelopment Analysis (TFDEA) methodology and applies an author-written Stata program for smartphone technology forecasting using TFDEA. We analyzed smartphone launch data from 2005 to 2020 to predict the adoption of smartphone technology and discuss the pace of technological change. The study identifies that the market is undergoing reorganization as new smartphone models expand the market and increase their technical performance. The average rate of technological change, the efficiency change, and the technology change were 1.079, 1.004, and 1.011 each, respectively, which means that the technology progressed over the period. When dividing before and after 2017, technological change and efficiency change generally regressed except for Huawei, Xiaomi, and Oppo. This means that Chinese smartphones are expanding the global market in all directions and the technology is reaching maturity and market competition is accelerating. Technology Forecasting using Data Envelopment Analysis (TFDEA); Malmquist Productivity Index (MPI); smartphone; state-of-the-art technology; dual-use technology; Stata +
Footnote †: journal: Applied sciences  
In order to use a smartphone with commercial technology for military purposes, it is necessary to select an alternative that can meet the military needs and target level. In terms of national security, new technologies are both a challenging threat to the protection of national key infrastructure and an important asset. The US Patriot Act of 2001 and Cybersecurity and Infrastructure Security Agency (CISA) states that \"Critical infrastructure includes the assets, systems, facilities, networks, and other elements that society relies upon to maintain national security, economic vitality, and public health and safety. Additionally, there are four designated lifeline functions--transportation, water, energy, and communications, which means that their reliable operations are so critical that a disruption or loss of one of these functions will directly affect the security and resilience of critical infrastructure within and across numerous sectors. For example, energy stakeholders provide essential power and fuels to stakeholders in the communication, transportation, and water sectors, and, in return, the energy sector relies on them for fuel delivery (transportation), electricity generation (water for production and cooling), as well as control and operation of infrastructure (communication)\" [9]. ROK also manages national critical infrastructures that are closely related to national operation and people's lives by ministries, and the communication infrastructure is considered as the critical infrastructure [10]. The development of smartphone technology has continued over the past 30 years, and about half of the world's population uses a smartphone in June 2021 [11]. Smartphones have rapidly spread since they were introduced to the world in the early 1990s and have become an essential tool in daily life, and there have been epochal changes in shape and performance. In addition, the foldable smartphone and 5G communication expected in the past have become a reality. Technological advances are good news for consumers, but companies that make products need a competitive strategy to survive. Technology-based companies need a strategy to develop core technology through technology prediction to respond to rapid technological change. Technology forecasting is a structured discipline which started by the United States Department of Defense and the RAND Corporation in the 1950s and was closely associated with military affairs [12].