In today's businesses, configurators are essential tools that allow customers to personalise a product to their specific needs. Being often the first contact between the retailer and the customer, it is important for a configurator to provide a smooth user experience. However, these software have been studied mostly from the reasoning point of view, that is, how to represent the logical relations between the configuration options and how to automatically ensure that the user makes no configuration error. In this paper, we focus instead on HCI and analyse the occurrence of 11 design flaws that occur in 28 car configurators. These flaws includes violations of general HCI principles as well as lacks of essential, configurator-specific functionalities. Our results indicate that most of the studied configurators contain defects in their UIs including, surprisingly, violations of some basic principles of HCIs. Still, the most frequent problems are inappropriate implementations of configurator-specific functionalities.
INTRODUCTION
The avenue of mass customisation – an established marketing
and engineering paradigm that unifies mass production and
customisation [
WII’18, March 11, 2018, Tokyo, Japan
car configurator where customers can choose between various
options like trim, motor, colour, accessories, etc. Beneath the
user interface lies an intelligent system that provides
effective guidance by preventing errors and providing automated
support for the configuration task [
Configuration knowledge refers to the set of rules that
determine what is a valid configuration. It originates from rational
(technical, legal, mathematical) and subjective (marketing,
aesthetics) knowledge. The acquisition of this knowledge is a
critical analysis activity for a successful configurator [
While efficient configuration engines exist, they are only a part
of the challenges in configurator engineering. Indeed,
configurators belong to a class of interactive applications where UX
is of paramount importance [
A prerequisite to creating these guidelines is to understand
what existing configurators do wrong. Therefore, pursuing
previous research [
AN OVERVIEW OF UX ISSUES IN CONFIGURATORS To carry out our study, we select a set of car configurators amongst the ten top-selling car manufacturers. For each manufacturer we choose the best selling car model, and for every model we consider the configurator of the US, UK and Belgium websites. This leads us to 28 configurators to evaluate (as two of the 30 candidates do not allow one to select any option).
Looking at these configurators, we rapidly note that basic
ergonomic guidelines [
In addition to these general considerations, we also observe issues related to the management of navigation within the UI. Figure 5 is a striking example that highlights multiple problems. First, we see that the interface does not display the step currently completed. Also it provides no visible way to go to the previous or the next step. The user has no idea of the progress she has already accomplished, and can neither consult nor preview the current state of her configuration. All these navigation-related issues constitute our second group of criteria.
Finally, we observe the lack of configuration-specific functionalities that are, however, deemed essential. For instance, Figure 6 depicts a configuration where three different sizes of wheels are selected. Errors are thus unchecked in this configurator. Configuration being a long and error-prone process, it is unrealistic not to help users complete their task. Explanation of errors, propagations and repairs – as presented in the previous section – are other facilitating functionalities. We argue that all configurators should implement them. Together with error checking, they are thus part of our third type of evaluation criteria. All our criteria are properly defined in the next section.
UX FLAWS: DEFINITIONS AND CRITERIA Based on our observations, we elaborated a list of common design flaws typically found in configurators. We categorize them into three degrees of specifity. The first degree comprises violations of general HCI principles that any application should satisfy. The second concerns issues related to navigation and are thus commonly found in interactive applications that represent a process. The last degree is related to the specific functionalities found in configurators, like propagations and repairs.
General HCI. We selected four types of violations that we deem critical in configurators. We settle for those, as our aim is not to perform a thorough analysis but rather to study how often such criteria are unsatisfied in practice. These are: Absence of feedback. No feedback is given to the user. There is no apparent result to her action.
Information overload. The quantity of displayed information is too high, or there is too much noise.
Too many controls. The UI displays too many controls on a single screen, or the number of controls needed to perform a single action is too high. Bad ergonomics. The configurator does not follow established ergonomics guidelines. These include, e.g., misplaced controls and inappropriate colour or font size. Navigation. Configuration being an interactive process, its navigation must be absolutely clear. We can see navigation from three points of view, i.e. in the UI, in the progress in the process, and in the configuration state. This leads us to four types of violations:
Unknown UI location. The user is lost within the UI and has no idea what step she is currently completing. Irregular navigation control. In the UI, the user cannot see the control allowing her to move to the next step, because their position or shape change.
Unknown progress. The progress in the process, i.e. what percentage of effort the user has already put in or remains to be done, is not displayed.
Unknown configuration state. The current state of the configuration (e.g. what options were selected, how the final product looks like) is not displayed.
Configuration. Finally, the lack of essential
configuratorspecific functionalities can lead to bad UX, as reported by [
Unchecked errors. The configurator allows the user to make incompatible choices, which lead to invalid configurations and ultimately to infeasible products.
No explanation. The configurator does not explain why errors are raised or why some options became mandatory or unavailable.
No repair. The configurator does not provide any repair functionality that helps the user fixing an error or changing her configuration, e.g., to make available forbidden options. RESULTS For each of the 28 configurators, we check whether its UI exhibits the 11 aforementioned design flaw. We first observe the occurrence of each design flaws. Accordingly, Figure 7 presents for each flaw how many configurators exhibit it. For general HCI principles, we observe that the lack of ergonomics is the most common pitfall, with as many as 21 configurators concerned with such issues. This is not totally surprising, as the ergonomics guidelines we consider are rather large, although we could expect better ergonomics in such customer-oriented applications. Information overload follows next, with half of the configurators being problematic. It is indeed common that car configurators have to deal with large amounts of options, hence the difficulty of presenting all these options while avoiding cognitive overload. 11 configurators contain too many controls. According to our observations, this is the result of overusing categorization to limit the number of options displayed to the user at once. Finally, only six configurators do not provide feedback. Overall, we notice that six configurators out of the 28 do not violate our general HCI principles, which may reveal an inherent difficulty to satisfying all these principles in this kind of application. Regarding navigation issues, seven configurator UIs do not present clearly the navigation steps that the user has to follow. Furthermore, the navigation controls are irregular in 14 cases, while ten configurators do not display any progress. More importantly, most of the configurators (23 cases) do not show the current status of the configuration, which is increasingly important as the number of options gets higher. These navigation problems likely interfere with the user’s experience; systematic solutions should thus be provided.
The most recurring problems, however, originate from configuration-specific functionalities. 23 out of 28 configurators do not systematically check the absence of errors, thereby authorising invalid configurations. We also identified 13 cases where explanations are not always given following an error or a propagation. Finally, 18 configurators do not provide automated repair each time they should.
Figure 8 gives us insights into the number of flaw types that occur in the configurators. We observe that half of the configurators violate more than six of our principles. This can be explained by the fact that the three configuration-specific functionalities are often missing altogether, while unknown configuration state and ergonomic problems are also pretty common. More surprisingly, only a quarter of the configurators comprise three violations or less. In the end, only one configurator does not contain any flaw. These observations tend to show the necessity of establishing guidelines to be followed by every configurator. These results clearly show that even though configurators are often infected by common UX flaws, the most important issues are specific to the configuration problem. These include not displaying the current configurator state and not providing essential configuration functionalities. Moreover, even if these functionalities were provided, there would remain the question of how to integrate them properly in a configuration UI. CONCLUSION Configurators are intelligent and highly-interactive systems that play a major role in today’s businesses. Despite their importance, our study reveals major issues in regard to their UX. On the other side, no HCI standards exist for these applications, and only few research work were interested in configurator UX. This motivates our long-term objective to design HCI guidelines specific to configurators, taking into account all their functionalities and particularities. In the future, we plan to expand our study across multiple industries in order to generalise our conclusions. This way, we also hope to identify the sources of the different UX problems, thereby paving the way to our envisioned elaboration of guidelines. Acknowledgement This work was partly supported by the European Commission (FEDER IDEES/CO-INNOVATION) and the Wallonia-Brussels Federation under the ARC programme.