This paper aims to suggest a multi-criteria decision making (MCDM) approach in the businessto-business context in order to evaluate the smartphone options and tariff plans offered by mobile service providers in respect to the taxi service operators' preference order. With the expert questionnaire filled by decision makers (DMs) of taxi service operating firms and real data collected from heterogeneous data sources, three MCDM techniques are utilized in the selection process: an analytic hierarchy process is utilized to set the relative weights of the smartphone and tariff plan evaluation criteria. Furthermore, the technique for order preference by similarity to ideal solutions and graph theory and matrix approach (GTMA) are applied to select an ideal smartphone and its relevant tariff plan for taxi service operators. The GTMA weights are obtained by the proposed self-written algorithms in RStudio software. The results show that the most ideal smartphone for taxi service operators is Lenovo A2016 (LTE) offered by Azercell mobile service provider. In addition, the most suitable tariff plan along with the smartphone is ''Optimist Talk'' with 3000 on-net and 300 off-net minutes, 300 SMS, and the 3000-MB Internet, which costs only 29 AZN per month. This paper fills the gap in the literature that no former studies combined above-mentioned three MCDM techniques to select an ideal smartphone as well as tariff plan, which are offered by mobile service providers. In addition, using three techniques, particularly the R script implementing the dynamicprogramming concept to calculate the assessed index scores for GTMA, significantly contribute to DMs in the B2B context to find an ideal solution not only in the mobile service but also in other domains.INDEX TERMS Smartphone, tariff plan, mobile service provider, MCDM, AHP, TOPSIS, GTMA.The associate editor coordinating the review of this manuscript and approving it for publication was Francisco J. Garcia-Penalvo. service providers. In addition, new generation smartphones are not the devices only for the communication purpose but are also comprised of distinctive features such as camera, internet access, calculator and others [3]. Smartphone users have different preferences and selection criteria associated with a smartphone and tariff plan. Haverila [4] indicated that male smartphone users put more emphasis on battery capacity, quality of hardware, ease of use, price and display size accordingly. On the other hand, female users prefer price, design, parts used, language selections and ringtones, while male counterparts prefer the features related to business service in smartphones [5]. Besides the camera, notepad and communication features of smartphones, they can also
