Usability challenges for mobile ERP systems
Todays, businesses have become increasingly reliant on information systems (IS) to support their business processes . Enterprise applications are examples of using information systems in businesses, in order to become more flexible and productive . One of the common examples of enterprise applications in practice are enterprise resource planning systems (ERP) . According to Laudon , ERP systems are widely used “to integrate business processes in manufacturing and production, finance and accounting, sales and marketing, and human resources into a single software system. Information that was previously fragmented in many different systems is stored in a single comprehensive data repository where it can be used by many different parts of the business”. The rapid technological advances in mobile computing are improving the way of doing today’s businesses . Enterprises started to migrate for the mobile strategy in order to meet the new requirements and expectations of their customers and business partners . The wide acceptance of using mobile devices at various levels has attracted the attention of many businesses to focus on incorporating their use, and capitalise on mobility to extend and expand the use of their designated ERP systems . In modern practise, a significant number of enterprises employ a strategy of “best of breed” for their ERP systems in order to strive for a competitive advantage, therefore, ERP vendors are scrambling to improve and extend their products features .
Mobile ERP term was suggested by Willis in 2002, as an extension and the future of ERP systems, that helps in solving the data capture problem . It permits the user to take the ERP system anywhere . Mobile ERP systems allow mobile devices to be connected to the back-end ERP system of an organisation through a mobile net of communications and transmission of data GPRS/UMTS . Figure 1 shows the mobile ERP systems components suggested by Gelogo and Kim .
A recent survey conducted by Redshift Research Ltd. which is commissioned by an international ERP software vendor via online interviews of 1 500 business professionals in ten countries. Respondents to the survey are using different ERP solutions. Nearly half of the survey respondents were in the manufacturing industry, one-third in distribution and logistics, and the remaining 20 % are in service sector companies. 22 % of respondents were in companies with up to 250 employees, 39 % were in companies with more than 250 employees, and 39 % worked in companies with more than 1 000 employees. Many findings from this survey related to mobile ERP :
“65 % perceive mobility as important to enable access to information and support communication for virtual workers.
Only 1 in 2 has any form of remote access to their ERP systems.
Only 25 % can access their ERP via smartphones and tablets computers.
In the future, 43 % want ERP access via their smartphones, and 38 % desire access via tablets.”
Usability as a quality measure for mobile ERP
The usability term was coined in 1980s, in order to replace the term user-friendly . There are different usability models; these models describe the usability attributes and its factors. In 1994, Nielsen defined five attributes of usability; efficiency, satisfaction, learnability, memorability and errors . The International Organization for Standardization (ISO) defines usability as:
ISO 9241-11 (1998): “The extent to which a product can be used by specified users to achieve specified goals with effectiveness, efficiency and satisfaction in a specific context.” 
ISO 9241-11 was developed by ISO’s group of experts specialising in human computer interaction from process perspective . Usability is the most important quality attributes for mobile applications . According to Harrison et al., the previous models used for traditional desktop applications, and the emergence of mobile devices added new challenges for usability, the fact, that previous models did not take into account these challenges, such as cognitive load .
In 2013, Harrison et al. introduced the usability model named People At the Centre of Mobile Application Development (PACMAD); this model considers the user, task and context of use as important factors to design a usable mobile applications , and it defines seven metrics to measure the usability of mobile applications:
- Effectiveness: the user’s ability to complete their tasks in a specified context.
- Efficiency: the user’s ability to complete their tasks with speed and accuracy.
- Satisfaction: the user level of comfort and pleasantness through the use of the software.
- Learnability: the ease of learning to use the application.
- Memorability: the ability of a user to remember how to use an application, if the system was not being used for a long period of time.
- Errors: lower error rate, error recovering and avoiding catastrophic errors are proposed by Nielsen, the PACMAD model extends the previous definition to include an evaluation of the errors while using mobile apps.
- Cognitive load: refers to the amount of cognitive processing required by the user to use the application, mobile application user are performing additional tasks, such as walking, unlike using traditional desktop applications.
Usability challenges for mobile ERP systems could be classified based on every entity involved in these systems; these entities are: mobile devices (smartphones and tablet computers), mobile context, mobile connectivity, mobile ERP user, and the back-end system (ERP).
Mobile devices (smartphones, tablets)
Smartphones and tablet computers vary in their features and specifications, actually, their capabilities are not comparable to desktop computers. The following is a brief explanation of mobile devices’ features and its technologies that pose usability challenges for mobile ERP systems:
Limited Screen Size: Mobile devices have a limited screen size compared to the desktop computer, accordingly, there is a limitation of the information amount that can be displayed, and there is a huge possibility to lose its meanings. Adopting ERP Systems over smartphones or tablets requires a completely new designed user interface, because of the limited space on the screens and operation via touch screen . This will adversely on user satisfaction of mobile ERP systems usage.
Limited processing and power capabilities: Mobile devices are less than desktop computers in the processing capability, memory and power . Therefore, some business functions and even ERP application features which were developed to facilitate the usage will be dispensed. As a result, this will directly impact on the usability of mobile ERP systems.
Data entry methods: Mobile devices are using touch-based interaction (virtual keyboard), which are different from those on desktop computers. A recent study by researchers at Northern Illinois University found that the average typing speed on a virtual keyboard was found to be 25 words per minute, compared to 63 words on conventional and notebook keyboards . Another study revealed that virtual keyboards had higher discomfort ratings than conventional keyboards . We conclude the following regarding into the usability, virtual keyboards reduce the input speed (efficiency), the probability of errors will increase (effectiveness) , and the end-users feel discomfort (satisfaction).
Diversity of mobile operating systems: People have strong personal connections to their devices and this will affect their satisfaction if they were forced to use a particular mobile operating system .
Security is a major concern of business owners when adopting mobile ERP systems. In spite of devices options that are available; bring-your-own-device (BYOD), choose-your-own-device (CYOD) and corporate-owned, personally enabled (COPE) devices, securing valuable data in ERP systems and devices from unauthorised access is compulsory, with having a balancing strategy between security and usability, without hinders the satisfaction of end-users.
Dey et al. defined context as: “any information that can be used to characterize the situation of entities (i.e., whether a person, place, or object) that are considered relevant to the interaction between a user and an application, including the user and the application themselves” 
The interaction between the end user of the mobile application and nearby people, objects, as well as environmental elements may distract user attention because the end-user will not be tied to a single location .
Besides that, performing additional tasks, while using mobile application (cognitive load), such as walking will cause distraction . According to the previous, mobile ERP user may suffer from distraction, which may lead to inaccuracy of data entry, and failure in completing business process (effectiveness), furthermore, it may slow down the business process completeness (efficiency).
Mobile connectivity attributes such as bandwidth and reliability will affect the usability of mobile ERP systems, the usability attributes for these systems such as effectiveness, efficiency and error are threatened in case of slow or loss of internet connection. On the contrary desktop computers have a stable connection to the back-end ERP systems.
The importance of the end user’s role in the interaction with applications push companies into designing and developing their products with user-oriented methods instead of technology-oriented methods . End-users with different levels of skills (e.g., novices, experts etc.) and ages need to be considered when adopting ERP systems in the mobile context. According to the European Commission report ”the 2015 Ageing Report“ , People aged 65 and over will become a much larger share of population by 2060, the expected rise percentage is 18 % to 28 % of the population, and this implies to: “the EU would move from having four working-age people for every person aged over 65 years to only two working-age persons” Elderly people usually have problems in the senses and movement, based on the previous citation, they will make up a large share of the labour force in the near future , and therefore, mobile ERP vendors should consider this from the usability perspective.
In recent years, several studies have shown specific usability challenges in ERP systems . One of these challenges is the ERP user interface; the user interface is considered an important layer of any system application, which allows end-users to perform the application functions. ERP systems are integrating and processing large amounts of data, therefore, their user interfaces are complex and rigid, and suffering from poor usability . These bloated user interfaces affect end-users effectiveness due to being lost . Mobile ERP is an extension of ERP systems , these systems may suffer from the usability challenges of ERP systems, furthermore, mobile ERP is currently still a young topic in practice and research .
Mobile ERP systems is the current wave of ERP systems, however, this wave is suffering from usability challenges, which can be classified based on every entity involved in these systems; mobile devices (smartphones and tablets), mobile context, mobile connectivity, mobile ERP user and the back-end ERP system. Therefore, ERP vendors should consider these challenges when adopting their ERP product into the mobile context. Mobile ERP is currently a young topic in practise and research, therefore, more researches and studies need to be conducted in this area. Enterprise application development teams need to use mobile applications development methodologies in developing their mobile enterprise applications, compared with using traditional methodologies (desktop applications).