-In ISO/IEC 25010, Quality in Use is mainly focused to the use of operators who interact with product and system directly. However, as workstyle using ICT (Information Communication Technology) has been changed, object of quality in use are also changed to not only direct users with simple direct interaction but also many stakeholders and society which are influence on indirectly by someone use the product, system and service. This paper proposes a Quality in Use model which corresponds to stakeholder needs. As for stakeholder, we classified four groups, that is -Operator of system and/or software, -Organization which has responsibility for system and/or software management, -Customer using system and/or software, -Society which exists system and/or software. As for stakeholder needs, we prepare “usefulness”, “managerial stability”, dependability” and “Acceptability”. To show the relationship among them, we proposed a new Quality in Use model. (Abstract) Figure 2. Proposal model of Quality in Use[4]
Importance of usability has been considered in not only
ergonomics area but also software engineering area[
In this figure, three quality characteristics (effectiveness,
efficiency, satisfaction) are same as usability elements defined
in ergonomics standard ISO 9241-11: 2018[
Recently, as workstyle using ICT (Information Communication Technology) has been changed, object of quality in use shall be not only simple direct interaction but also many stakeholders and society which are influence on indirectly by someone use the product, system and service. That is, ICT users are not only direct users who interacts system and product directly but also indirect user who use output obtained by using ICT.
Direct user means a user who interacts with product, system
or service directly. For example, ATM users in banking
system, customers for electric commerce system. On the other
hand, there are the other kinds of users, they are indirect users
of other stakeholders. They usually use an output of products
or system. For example, in case of self-driving car (level four
or low), a driver is one of direct user and operators of traffic
infrastructure are kinds of secondary user. As for pedestrians,
they are indirect users. Figure 2 shows the proposal concept
of quality in use include other stakeholders[
III.
As system and software products are widely used in our life, use of them is influence on not only their direct uses but also organizations and society.
It is responsibility for society of the manufacturer to be controllable these influence as much as possible.
From this, quality is regarded influence on stakeholders
by using. The purpose of quality in use is that manufacturers
and managers are able to enforce to “use” for improvement
of quality by measuring and evaluating.[
The objectives which are influenced by use of system and software in not only their direct users but also indirect users included various kinds of stakeholders. Contents of influence (quality characteristics) are different by the difference of objects. From this, we classify these objects into four groups shown below and quality in use model for each group is defined.
-Operator of system and/or software -Organization which has responsibility for system and/or software management -Customer using system and/or software -Society which exists system and/or software
The reason why groups are four is to be able to explain almost situation by these four groups, i.e. stakeholders.
When “quality in Use” is considered, it is necessary to clarify which group is focused because quality models for use of system and product are different by the difference of objects described above.
In this paper, “Quality in Use” is defined as follows: Quality in Use is that degree to the system satisfied the stakeholder needs related to use when operator uses the system and software.
Figure 3 show the quality in use models for four groups.
In this figure, each box about quality in use, that is, “quality in use for responsible organization, people”, “quality in use for operators”, “quality in use for customers” and “quality in use for society” is object group of quality in use, respectively. Below four boxes describes influence by use.
In this, “quality in use for operators” is correspond to the original quality in use model. As this model mainly focuses on direct user, we consider that elements of usability defined in ISO9241-11:2018 should be adopted as quality characteristics in this model. Quality characteristics for the other three objects shall be defined by terms which represented each influence suitably.
In ISO/IEC25010, the quality of a system is defined that the degree to which the system satisfies the stated and implied needs of its various stakeholders, and thus provides value. Refer to figure 2., stakeholder needs for quality in use can be divided following four items; they are “usefulness”, “managerial stability”, dependability” and “Acceptability”. The relationship between stakeholders and stakeholder needs are shown in figure 4. This figure is proposed quality in use model. IV.
[2] ISO/IEC 25010: Systems and software engineering -Systems and software Quality Requirements and Evaluation (SQuaRE) — System and software quality, 2011