Usability of Mobile Applications

Dissemination of Usability Engineering in Small and Medium Enterprises

Britta Fuchs, Thomas Ritz and Jakob Strauch

Faculty of Electrical Engeneering and Information Technology, FH Aachen, Eupener Str. 70, 52070 Aachen, Germany

Keywords: Usability Engineering, Mobile Applications, SME, User-centred Development.

Abstract: This paper starts from the idea that mobile enterprise software has great potential in the future but needs to

fulfil usability requirements to be successful. Following mobile enterprise software Mobile enterprise

software is explained with the established software engineering processes. Related to this topic usability

engineering is presented with relevance to the utilization in small and medium-sized enterprises (SMEs).

The relevance of the target group SMEs is demonstrated using the example of Germany. The integrated

user-centered method for mobile enterprise software development integrating usability is presented. The

paper closes with an analysis of the needed future research in this field.

1 INTRODUCTION

Mobile enterprise software systems increasingly turn

out to be suitable for integrating external workers of

small and medium-sized enterprises (SMEs) into

operational information logistics. However, in terms

of usability mobile software systems differ have

features that were responsible for the failure of many

such projects in the past.

This paper will first explain mobile enterprise

software and usability engineering. Based on this the

usability criteria are highlighted that need to be

considered when developing mobile enterprise

software for SMEs. Then, the requirements for an

adequate approach to take usability criteria and

needed tools into account are derived.

2 MOBILE ENTERPRISE

SOFTWARE

The concept of enterprise software is established as

a diffuse summary of business application systems.

The goal of mobile enterprise software is the

involvement of employees who do not work at a

fixed location. Especially in machine and plant

construction, the provision of services is a task that

is often done by the field staff.

The following definition of mobile enterprise

software (Ritz, 2003) enlarges this idea with

important requirements:

"Mobile enterprise software is the application of

business software solutions in mobile use

1. on appropriate mobile devices

2. with appropriate functionality

3. based on appropriate data currentness. "

From this definition immediately result a set of

requirements concerning a development approach of

mobile enterprise software solutions (see Table 1).

Initial approaches to consider localities in the

requirements analysis and related infrastructure

issues are integrated e.g., in Mobile Process

Landscaping (Köhler and Gruhn, 2004). There are

also many variants and extensions of UML (e.g. M-

UML Saleh and El-Morr, 2003, agile M-UML

Baumeister, 2005) involving mobile aspects, but

address the modeling of requirements less than

modeling contexts for autonomous mobile systems

and user profiles.

Our research group was able to develop a tool

that extended UML with the stereotype location and

that makes characteristics of the user (actor), e.g.

about his mental abilities ascertainable (Ellerweg

and Ritz, 2008a, Ellerweg and Ritz, 2008b).

Especially for the development of mobile service

solutions there is no adequate modeling support to

systematically record and document any special

requirements during the requirements analysis.

272

Fuchs B., Ritz T. and Strauch J..

Usability of Mobile Applications - Dissemination of Usability Engineering in Small and Medium Enterprises.

DOI: 10.5220/0004068802720277

In Proceedings of the International Conference on Data Communication Networking, e-Business and Optical Communication Systems (ICE-B-2012),

pages 272-277

ISBN: 978-989-8565-23-5

 2012 SCITEPRESS (Science and Technology Publications, Lda.)

Table 1: Core elements of mobile software engineering.

Location and context must be considered in

the specification of software. In particular, a

change of location where an application is

used causes alterations e.g. on the available

network infrastructure or the environment

situation (noise, light ...).

Such requirements must be imposed within the

software engineering process and their

fulfillment need to be checked in test scenarios

Interaction and basic paradigms differ from

stationary to mobile applications. Working

with mobile IT systems is often characterized

by short and frequently interrupted activities

(Salmre, 2005).

The applications must be adjusted accordingly.

It should be regarded that in mobile business

processes often people with a limited affinity

for computer applications are involved. The

specific requirements have to be collected as

part of the software engineering process.

Multitude of possible devices are available

with very different characteristics (Hansmann,

Merk, Nicklous, & Stober).

Selection and use of these characteristics has

to be central element of the software

engineering process.

A variety of architectural options is available

specifying in particular whether data is stored

on the mobile device or stored centrally (Roth,

2005). The definition of a suitable architecture

is therefore a central element of a software

engineering process. Doing so it must be borne

in mind that architecture components such as

networks are not consistently available or are

encumbered with additional costs.

The software engineering process has to

methodically identify main activities the user has to

fulfill in parallel (e.g. repair work) that may interrupt

the use of the mobile system (Salmre, 2005). To be

able to cover the requirements of the individual user

as good as possible, the particular user abilities have

to be integrated into the development process.

Additionally the software system should be created

in close consultation with the users.

To meet the demand for customized

functionality, user-centered design methods have

proved themselves (Norman & Draper, 1986). They

as well lived up to the expectations when it comes to

integrating customers beyond interaction into

software projects as an important input factor.

The customer as most important input factor is

consulted in iterations to (re-)define both, the

requirements and the acceptance of sub-projects.

The most important representatives of iterative

software development methods are Extreme

Programming (Beck & Andres, 2004), Crystal

Methodologies (Cockburn, 2005) or Scrum

(Schwaber, 2004). Usually the methods focus the

engineering-based approach to software

development and management of resources (see e.g.

Cooper, Cronin, & Reimann, 2007).

These approaches aim to handle user-centered

functional requirements. In contrast measures of

usability engineering (Mayhew, 1999) target to

integrate the definition of usability criteria

(effectiveness, efficiency and satisfaction) (DIN EN

ISO 9241-1) into the development process and as

well to verify those criteria. Our research aimed at

developing an integrated method combining both

approaches, extreme programming and usability

engineering.

3 USABILITY ENGINEERING

Usability is understood as the degree of

effectiveness, efficiency and satisfaction in which

users can perform certain tasks with an application

in a given environment (e.g., office environment)

(see DIN EN ISO 9241-1).

In this context process models have been

established that systematically consider usability as

a performance measure, covering the entire product

life cycle. These process models can be summarized

under the term "usability engineering" (see e.g.,

Mayhew, 1999).

While user interface design addresses mainly

visual user interface design, usability engineering,

describes both, the development of interactive

systems and as well the design of appropriate work

practices and interactions of users in the specific

context of use. Therefore, usability engineering

influences the design surface, but is not limited to it.

More advanced software development is

increasingly beyond the aspect of usability and is

dedicated to the field of user experience. User

experience describes the "perceptions and reactions

of a person resulting from the actual and / or the

expected use" of an application (DIN EN ISO 9241-

210).

User experience adds a clearly hedonic

component. It is characterized by aesthetics, fun,

functionality, enjoyment and personal development

(Hassenzahl, 2004) but as well by the brand image.

The latest developments such as the success of the

Apple iPhone illustrates that even supposedly non-

interactive design domains benefit from user

experience (Klauser and Walker, 2007).

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273

On the one hand, user experience affects

interaction and interface design. On the other, user

documentation and support service as well as

maintenance have to be considered. In order to meet

these requirements the users strengths, limitations,

preferences and expectations have to be taken into

account (DIN EN ISO 9241-210).

With regards to medium-sized companies

employing software the following key findings were

identified by the research project “Usability in

Germany“ (Woywode, Mädche, Wallach, & Plach):

• In certain software employing enterprises

usability is an explicit purchase criterion

previous to other criteria such as price or

functionality.

• Software with a high degree of usability is

created primarily by software producers with a

strong user orientation. These criteria can be

found in companies where management has a

positive attitude towards usability and where

extensive knowledge regarding usability is

available within the company.

• In addition to the perceived customer

requirements the interaction in the

organizational area contributes significantly to

mental attitude and knowledge development.

• Software producers who assess a high usability

degree of their products recorded an above-

average corporate success in recent years (as

measured by customer satisfaction and sales

performance).

4 TARGET GROUP SMALL AND

MEDIUM ENTERPRISES

In the online survey "Questionnaire User Need"

(FUN), SMEs were asked about their need for

usability. The survey concludes that in medium-

sized businesses a general acceptance of usability

services exists. Once companies were aware of

usability issues, they were more open to external

services.

A majority of the SMEs surveyed considers that

the application of usability methods in earlier stages

of development of suitable and desirable. More than

70 % of the respondents subjectively assessed their

own products as sufficient easy to handle. That’s

why they could not find a reason to increase the cost

of usability measures in the future (Brau et al.,

2011).

While 1,000 companies were asked to participate

in the survey, the results are based on the records of

only 41 companies. Since it is possible that the other

companies did not respond because they are

uncertain, how to deal with usability the findings of

the survey apply only as indicators. A large

proportion of medium-sized German software

companies is still in its infancy with respect to this

issue (Woywode et al.).

Since a couple of years, the relevance of

usability for products and services is recognized.

While theoretical knowledge regarding usability is

described in a number of norms and standards, it is

not much employed. This can be understood as an

indication that the processes are not suitable for the

SME target group yet. It is therefore not sufficient to

build skills and expertise relevant to the user-

centered software development. The conventional

methods must be examined under the particular

conditions for SMEs.

In the industry of information and

communication the Federal Statistical Office

Germany lists in total 130 311 enterprises. The

majority of those enterprises has between 0 and 9

employees (120,140 companies) and belongs

therefore to the micro enterprises. 7,823 companies

employ between 10 and 49 employees. 1,953

companies employ between 50 and 249 people. Only

395 large-scale companies are registered in this

branch. It is expected that the positive developments

in the German software market in recent years will

continue. According to forecasts business volume is

expected to nearly double to 40.6 billion € (A.T.

Kearney, 2008) by 2020. Extrapolated to the

European Union and worldwide this paper assumes

that there is a lot of money in this market. The target

group of SMEs seems to be a very lucrative one.

5 USER-CENTRED

DEVELOPMENT FOR SME‘s

Subsequently, the Integrated Method integrating

usability into the mobile software engineering

process is presented and explained. It provides a

guideline for the professional usability engineering.

It turns out that it needs to be adapted to the

requirements of small-and medium-sized software

companies. The procedure can be divided into two

phases. In the first phase a generic requirements

analysis is accomplished. The steps are based on the

"Usability Engineering Lifecycle" by Mayhew (cf.

Mayhew, 1999). The result of this phase is a first

early prototype. To understand the basic operations a

superficial process analysis is conducted (step 1).

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Figure 1: Integrated Method.

While doing so obvious problems are documented

and people involved in the process are determined.

For this well-known methods of process modeling

may be used as well as the (contextual) Task

Analysis Table proposed by Mayhew (see Mayhew,

1999).

As an extension with regards to mobility aspects the

possible vicarious places and local types of the

individual applications are collected. Common

process notation can be enriched by mobile process

landscapes proposed by Kuhn et al. (cf. Köhler and

Gruhn, 2004). For an integration into BPMN see as

well Damm (Damm te al., 2010).

Detailed user profiles are collected for persons

and groups of persons who are affected by a future

IT solution (step 2). In this step established methods

of usability engineering are used as well (specific

approaches for mobile applications can be found in

Jones and Marsden, 2006 or Love, 2005).

In step 3 the technical infrastructure is examined.

Finally, already existing design guidelines and

standards will be collected and analyzed with

regards to their applicability (step 4). Besides

general design guidelines for mobile applications

product-specific guidelines (e.g., Apple HIG Apple,

2011) can be consulted.

Based on the knowledge gained a first prototype

solution will be developed (see also Casaday &

Rainis, 1995, Beyer and Holtzblatt, 1999). This first

prototype don’t need to be fully digital and

interactive (see e.g. Holzinger et al., 2011), but

rather can be visualized in the form of drawings, etc.

(for the use of prototypes for mobile applications,

see Jones and Marsden, 2006; Love, 2005). These

prototypes will be evaluated by users, e.g. in form of

using scenarios.

If shortcomings in the conception emerge, those

findings have to be continuously integrated as

improvements in new prototypes. The described

iterations are accomplished until the customer is

satisfied with the outcome of the project or the

project's budget is exhausted.

This is a dramatic reversal of the established

treaty and implementing systems for software

products. Those established systems even do not

enable the use of agile software development

Usability of Mobile Applications - Dissemination of Usability Engineering in Small and Medium Enterprises

275

methods in SMEs. As an indication especially

usability could measure customer satisfaction as an

appropriate "termination criterion".

The customer feedback on the first prototype

provides the input for the first iteration. Now the

customer has a much better idea about the

possibilities of mobile enterprise software than

during the requirement analysis phase. With this

knowledge the customer defines use cases (step 6).

The use cases are evaluated in particular with

regard to their development efforts and are translated

into task cards by the developer (see Wells, 2001)

(step 7). Finally the customer selects the "stories"

that can be implemented with the available resources

during the upcoming iteration period (step 8).

Based on this selection the usability testing is

being prepared. According to Mayhew (Mayhew,

1999) it will be initially decided whether priority is

given to "ease-of-learning" or "ease-of-use". Then

goals are provided, performance measures identified

and finally thresholds determined. For example the

goal of self-descriptiveness could be measured by

the average error rate for a particular task.

As mentioned above, these metrics arise from

experiences SMEs often are not able to access. The

parameters and the description of use cases together

with the derived test environment (context) are

combined to a usability testing plan. Now the

developer implement the selected use cases based on

the usability requirements using the XP paradigms

(see Wells, 2001) (step 10).

Here it is important to create transparency that

usability criteria are used not only for approvals but

also can be used as a development goal. Ideally the

usability tests simulate the environmental conditions

of the documented site for the according use case.

With the help of the usability tests the defined

usability performance measures are collected and

compared with the defined target values (step 12) in

order to be able to comment the usability of the

iteration results. The outcomes result in change

requests and provide new use cases (again, step 6).

Together with the in the current not implemented

use cases this is the start for the next iteration.

6 DISCUSSION, CONCLUSIONS

AND FUTURE WORK

The method of user-centered design of mobile

enterprise software has been in successfully applied

in numerous teaching and research projects by staff

members and students. Regarding the application of

the method and user-centered development in

general in SME software projects problems occurred

that have to be solved with future research in order

to meet the demand identified in this paper:

• Experience is required for a more targeted use of

the variety of methods. So far, knowledge is

lacking what methods are suitable elements for

SMEs and what not. Suitability depends on the

SME and its business goals themselves as well as

on project objectives, timeframe, skills and

competition.

• The complexity of influences on usability aspects

requires a broad range of expertise. A division of

competence profiles on different does not seem

feasible for SMEs. Usability engineering for

SMEs will be streamlined by the proposed

method. The method has to be defined in a way

that the individual steps can be associated with

clear job profiles and thus competence profiles

(usability engineer, developer, interaction

designer).

• Standardized and formalized processes can be

important especially for occasional requirements

engineering. Templates for surveys, personas,

scenarios and use cases help to omit any

requirements. This large number of artifacts of

different media has to be managed centrally. But

a corresponding "pragmatic" tool does not exist

yet.

• The artifacts also serve to document the surveys.

It is of particular importance that the knowledge

of all parties involved (conceptual creator,

designer, developer) can be retrieved. There is a

lack of solutions as well.

• Besides various style guides the knowledge of

good and bad approaches of interaction concepts

is elusive. There are no central, easy to search

collections of best practices or animated style

guides for software developers available.

Those topics are addressed within a research project

of the German Federal Ministry of Economics and

Technology (BMWI).

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