ATAG combi-oven redesign
The goal of the project is to create an adequate redesign, by solving
problems experienced in a conducted user test with the ATAG combi
microwave oven CX4511D. This redesign is tested again, after which
other problems were identified.
The changes in the redesign focused on navigation, stage cooking,
programs and favourites. The navigation was changed to be more
consistent and intuitive. Stage cooking, programs and favourites are now under the same functionality, which is named ‘recipes’.
The user test of the redesign confirmed that the effectiveness and
efficiency of the interface improved. The participants also experienced the redesign much better and rated it higher on pragmatic qualities than the original product. Evaluation of the design goal also confirms that the redesign was successful. ​
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Company
ATAG
My role
UX researcher / Interaction & UI designer
Time
24 weeks / School project
2017. Feb. - 2017. Jun.
Background
The CX4511D combi microwave oven is one in the Matrix line of ATAG. With a price of € 1.499,- it positions itself below the Magna line (CX4574M), which is € 2.099,-. The Matrix line is the mid-range line of ATAG and this product is best tested by the consumers association. The product is ‘consumers’ choice’, because of its wide variety of functions - combined with high quality - for its price range.
Context of use
The kitchen is the environment of a combi microwave oven. The quote on the previous page describes what factors are of importance in a cooking enthusiast´s kitchen. Some context factors also influence the interaction with the product. These factors are explained here.
Target Group
The ATAG combi microwave oven can be used differently within every context. The primary focus of this project is on the context of:
Cooking Enthusiasts
Such group uses more functionalities of the product than other types of users such as students other or elderly. ​
The price range of the product is also more suitable for such users, who are also the target customer of ATAG.
Product system flow chart
The system flowchart of the combi microwave oven shows below. Each column (default setting, Main functions, etc.) represents one layer of the product system. The horizontal flow describes the steps that the user is able to go through.
Project process
In this project, the usability of the ATAG combi microwave oven was evaluated by the users. Based on the evaluation result problems were defined and identified. From this evaluation, a design brief follows. The design brief will give the concrete goal of the redesign together with the requirements. With the insights and inputs, the new design was developed to address the problems that users encountered during the usability testing. The second evaluation of the redesign was similar to the first product evaluation, and the results were analysed in a similar process. The result of two evaluations - the product and redesign, will be compared to understand the improvements.
Usabitity test
Goal of the test
The main goal of the user test is stated as:
Identify usage issues of the ATAG combi microwave oven for
cooking enthusiasts.
1. Effectiveness - to what extent can users manage to do what they
need to do?
2. Efficiency - how well can users do what they need to do?
3. Satisfaction - how does using the product make the users feel?
The subgoals, used to achieve the main goal, are:
• Identify the strengths and weaknesses of the product,
• Identify if the users feel restricted in operating the ATAG combi
microwave oven and what they are limited by,
• If the users will already show some patterns.
Testing process
The usability study is conducted by asking participants to perform four tasks. Quantitative data will be gathered during participants performing the task, and qualitative data will be gathered in the retrospect evaluation section by conducting a short interview and two questionnaires.
Testing Result
The results of the product evaluation are presented in this section. The results are divided in performance, how the tasks were performed by participants and experience, how participants evaluated the usability of the product.
Problem Define
All problems that occurred during the user tests and led to our design goal. The table below shows an overview of all the problems. The problems related to the interface are divided into two categories: use and goal. In each category, the problems are categorized in four groups: ‘missing information’, ‘inconsistent information’, ‘wrong information and ‘insufficient information’.
Design Goal
To achieve our design goal, few requirements were set based on the identified problems. If these requirements are met, it enables users to feel in control while operating the system.
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The qualities trustworthy, responsive and clear represent feeling in control.
“Enable a cooking enthusiasts to feel in control when operating the interface of the combi microwave oven.”
Requirements
1. The layer depth of a menu is clear by having a maximum of 4 layers.
2. The interface provides the user with information about the layer depth.
[ Programs and Favourites function ]
3. Programs & Favourites only allow a single way of navigating
4. Programs are more transparent, by displaying the functions that are used on the interface.
5. The distinction between the level setting (min/normal/max) is clear by using terms cooking enthusiasts are familiar with.
6. Favourites should be editable
[ Stage cooking function ]
7. Stage cooking can be found in a maximum of two steps
8. Navigating through stage cooking is clear by only allowing a single way of navigating
9. Editing or deleting a stage in stage cooking can be understood at once in the first time use
10. Stage cooking is easy to start by allowing a single way of navigating
11. Stage cooking is easy to start by making the way of starting consistently with the other functions of the combi microwave oven
Redesign
5.1 Physical Elements
The only changes made in the physical elements are the changes in the visual appearance of the confirm key, and
the change from the programs and favourites icon into the new “Recipes function” icon.
5.2 Digital Interface
To achieve our design goal, few requirements were set based on the identified problems. If these requirements are met, it enables users to feel in control while operating the system.
The qualities trustworthy, responsive and clear represent feeling in control.
5.3 Navigation
The most successfully tested navigation rules were as followed:
• Horizontal navigation can always be performed by the navigation keys
• Horizontal navigation can be performed by the selection knob, if there is only one adjustable parameter in the screen.
• Pressing the selection knob means “select”. This means that you select the chosen parameter and continue to the following
parameter.
• The confirm key is only used as a key for final confirmation (e.g. starting the oven). To communicate this clearly, the confirm key
has been redesigned to the start key
Redesign Evaluation
Setup & Task
The digital prototype was made with Principle, a digital prototype software. However, the digital prototype did not allow for physical knobs, because everything needs to be one screen. That is why the rotation knobs are made into two digital knobs; turning left and turning right. The screen of the Ipad used to show the prototype was covered by a paper prototype that resembled the oven.
In the study, participants were asked to perform five tasks.
Task 1 - Using the microwave to prepare corn
Task 2 - Make a roast beef using programs
Task 3 - Grilling chicken breast in the oven & adding a favourite
Task 4 - Deleting a favourite
Task 5 - Using different temperatures to make roast chicken with my recipe
Result
In this section, the results of the redesign evaluation are showed. The first part of the results is focused on the performance. After performing the tasks using the prototype, the participants indicated how they experienced the product through three different questionnaires: - SUS, AttrakDiff and a design goal questionnaire.
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