Mobile Development Process Spiral Ann Nosseir, Faculty of Informatics and Computer Science British University in Egypt, ann.nosseir @bue.edu.eg Derek Flood Dundalk Institute of Technology derek.flood@dkit.ie Rachel Harrison, Department of Computing and Communication Technologies Oxford Brookes University rachel.harrison@brookes.ac.uk Osman Ibrahim Faculty of Informatics and Computer Science British University in Egypt, Osman.Ibrahim@bue.edu.eg Abstract—Recent advances in mobile technology have led to ever- increasing demands for specialized software for these devices. Furthermore, the need for mobility has introduced unique constraints such as context, connectivity, size and data entry methods that impact on the apps’ usability. These constraints can create usability errors that could increase risk levels especially in contexts like finance, health, or road navigation. The desire of Enterprises to embed their mobile apps’ development into their business cycle increases the need to have a specialized software development process. Although many agile methods have been introduced over the last decade, none of methods has focused on reducing usability errors. This paper proposes a novel Mobile Development Process Spiral which is a Usability-Driven-Model. The process is designed to integrate usability into existing application development processes and recommends usability techniques for assessing mobile apps. Keywords; mobile software development, spiral model, user center design, usability I. INTRODUCTION: Recent advances in technology have increased the capability of mobile devices while simultaneously reducing the amount of space necessary for such devices, allowing them to be used while on the move [1]. There are now 5.3 billion mobile subscribers i.e., 77 percent of the world population [2]. In 2010, Mobile devices’ sales rose with a strong growth in sales of smart phones. The main functionality of smart phones is communication. Broadband and Wifi Internet access has increased mobile Internet usage as it allows mobility, quick responses, time management and communication [2]. Adding more features such as GPS, cameras, and Bluetooth has allowed more mobile apps to be developed in domains like gaming, entertainment, banking, finance, sports, music, travel, health, and personal care. Enterprises started to see the potential of using mobile apps in their business cycle. For example, “Pizza Hut CIO, Baron Concors, confirmed that Pizza Hut foresees the mobile experience as an extension of the brand. payment capability over the mobile phone (via web-based payment gateways or Near-Field Communications (NFC)), location-based messaging, and mobile chat features round-up the other three major elements of a mobile retail platform strategy [2].” ABI Research recently released a report which predicts that the sports and health mobile app market is on pace to hit $400 million in revenues by 2016 [2]. Realizing the advantages of mobile apps, more resources were allocated to improve the company’s standards. This progress has pushed the software application market to boom and more specialized mobile software companies are evolving. To compete with the market pace and competition, these companies apply a rapid software development process cycle such as agile software development. However, this approach usually does not allow detailed evaluation to minimize mobile apps problems and errors. Although the processing power of mobile applications has greatly increased in the last few years, the features of the mobile device (such as size) have introduced many usability constraints. One of the most common tasks for tourists while on holidays is navigation around an unknown location. Through the use of GPS (Global Positioning Satellite) technology, users can use mobile devices to find their current location, plan a route to their destination or to find points of interest. The limited screen size of these devices however can make it difficult for users to read on-screen maps. As well as navigation, mobile devices can also be used for searching the Web. However the small screen size coupled with the limited interaction methods and poor connectivity, affect the users’ ability to successfully search for specific pages and to find the information they require on these pages. The examples presented above are just some of the constraints imposed by mobile devices that impact the usability of these applications. Zhang and Adipat [3] detailed a number of these challenges. • Mobile Context: When considering mobile applications the user is not tied to a single location. Environmental constraints also include interaction with nearby people, objects and environmental elements which may distract the users’ attention. • Connectivity: With mobile devices connectivity is often slow and unreliable and therefore will impact the performance of mobile applications which utilize these features. • Small Screen Size: In order to provide portability mobile devices have very small screens meaning that the amount of information that can be displayed is drastically reduced when compare to a PC. • Display Resolution: The resolution of mobile device screens is not as good as that of desktop computers resulting in a lower quality images. • Data Entry Methods: The input methods available for mobile devices are constrained and require a certain level of proficiency. This problem increased the likelihood of erroneous input and decreases the rate of data entry. 978-1-4673-2961-3/12/$31.00 ©2012 IEEE 281