# Leveraging the Internet of Things and Blockchain Technology in Supply Chain Management
## 1 Introduction  
Supply chains are becoming increasingly heterogeneous and complicated due to a growing need for inter- and intra-organizational connectedness, which is enabled by advances in modern technologies and tightly coupled business processes [1; 2]. To cope with this dynamic environment and the increasing need to digitize supply chains and enhance competitiveness, companies are applying novel technologies such as the Internet of Things (IoT), cloud computing, business analytics, artificial intelligence, machine learning, and Blockchain technology [3; 4; 5], as well as innovative concepts such as the so-called physical Internet [6]. The multiplicity of technologies, which are often simultaneously introduced, along with the ubiquity of connected devices, often labeled as'smart' devices or things, allow value chain exchange (or trading) partners to reach new levels of effectiveness and efficiency [7]. These technologies promise to reshape the modus operandi of modern supply chains through enhanced data collection as well as information sharing and analysis between collaborating supply chain stakeholders [8]. Moreover, they enhance information transparency, leading to increased trust between the exchange partners [9; 10]. The impact of these technologies on supply chains constitutes a research gap that is relevant for both practitioners and academics. IoT is defined as a \"group of infrastructures interconnecting connected objects and allowing their management, data mining and the access to data they generate\" [11] (p. 73). It embodies the next phasetoward mass digitization of supply chains to facilitate the so-called Industry 4.0 [12]. IoT encompasses devices such as sensors as well as passive, semi-passive (or semi-active), and active Radio Frequency ID tags (RFID), and other electronics which are connected over a network. Together, these technologies can perform numerous tasks, including functions such as sensing activity, movement, or temperature; actuating and collecting; processing, storing, and sharing data. For example, the food supply chain is particularly sensitive to environmental conditions during transportation and storage, such as light, humidity and temperature [13]. In the cold chain, time-temperature measurements with sensor devices connected to a wireless sensor network (WSN) can help to preserve the quality and safety of a food product and reduce the risk of spoilage [14]. WSNs represent a network or system of connected sensors which communicate to a base station through mobile networks such as 4G or GPRS (General Packet Radio Service) and informs supply chain exchange partners in real-time [14]. When the information is received, it can trigger an acceptance or rejection of the shipment based on the temperature parameters preset in a smart contract, which in turn can trigger payment if accepted. Moreover, when IoT-enabled sensor devices connected to a WSN provide time-temperature alerts on a real-time basis, an out of tolerance measurement (or a predictive out of tolerance measurement) can trigger a mid-shipment corrective action and intervention by the driver or shipper [8; 9]. The growing economic importance of IoT reflects in its steadily increasing industry adoption. With the convergence of information and communication technologies (ICT) and machine automation, the use of IoT has become more pervasive, especially in supply chains and logistics. This trend is attributable to increased computational power and decreased costs of the connected devices. The International Data Corporation (IDC) forecasts that by 2021, 20% of the largest (G2000) manufacturers will depend on a secure infrastructure backbone of embedded intelligence to automate large-scale processes and enhance the speed of process execution by up to 25%. This backbone will mainly depend on IoT for enabling controls and actuators to take autonomous decisions [15]. In 2017, there was an estimated 5 billion IoT enabled devices, and this number is expected to reach 29 billion by 2022 [16].