Revamping Coop's Self-Checkout Systems

About the project

In my master's thesis, alongside two collaborators, we embarked on a mission to redefine the self-checkout experience for Coop customers. Our goal was to enhance user satisfaction and operational efficiency by applying Goal-Directed Design principles. This journey took us deep into the ecosystem of Coop's self-checkout, aiming to streamline the purchasing process and elevate the overall user experience through close collaboration with Coop.

Jump to

• Research Phase
• Analysis & Modeling
• Design Phase
• Usability Testing
• Final Deliverables
• Retrospective

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Project Scope and Initial Discovery

Coop introduced its Self-Checkout (SCO) systems in 2012, achieving initial success by reducing checkout times and increasing customer convenience. Over time, however, it became evident that the systems suffered from limited development, relying heavily on outdated concepts. This project represented Coop's first foray into user-centered SCO system improvement, with a specific focus on enhancing accessibility, in line with the upcoming European Accessibility Act (EAA) standards.

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Deep Dive into Research

The journey began with a Scoping Workshop, bringing together Coop stakeholders and our team to define the research direction. This collaborative effort resulted in a detailed understanding of the existing SCO ecosystem, uncovering challenges like prolonged waiting times, usability issues, and high service costs associated with cash transactions.

The initial Scoping Workshop with Coop stakeholders uncovered pivotal areas for our project's focus:

• Long Waiting Times: Highlighted by bulk buyers’ tailback and technical failures impacting self-checkout availability. Inadequate staffing for random checks and unclear indicators for available checkouts exacerbate the issue.
• Usability Improvements Needed: Challenges include identifying PLU-items, the inefficient process for weighable items, frequent checkout interruptions, unclear communication of scanned discounts, and insufficient space at checkout areas.
• High Service Costs: Primarily driven by issues related to cash acceptance, such as technical malfunctions from jammed coins, contributing to a significant portion of service cases.

These insights informed our project direction, emphasizing the need for a user-friendly, efficient checkout experience that addresses waiting times, usability, and service costs.

User Research: A Two-Phase Exploration at Coop Stores

In the vital user research phase of our project, we delved into the environments of selected Coop stores across Zurich, Basel and St. Gallen. This immersive approach enabled us to gather firsthand insights through methodical iterations, each with distinct objectives.

First Iteration:

• Objective: Observe how users interact with self-checkout (SCO) systems and to verify whether the challenges identified during the scoping workshop reflected actual user experiences.
• Locations: Four diverse Coop stores were chosen for research, including Coop Zurich Bahnhofbrücke, Coop Zurich Letzipark, Coop Basel Erlenmatt, and Coop Basel Gundeli.
• Methodologies: 5 Expert interviews, 13 contextual inquiries and fiel observation were systematically conducted to gather insights into user behaviors and challenges.
• Eyetracking: Eyetracking tools such as "Tobii nano" and "Pupil Invisible" were utilized in one store, Coop Basel Gundeli, to capture eye movements and activities during interactions with self-checkout screens.

‍Second Iteration:

• Objective: Following reflection on initial findings, a second iteration was conducted to validate assumptions, particularly regarding the behavior of weekly shoppers (bulk buyers) using self-checkout systems.
• Location: This phase was conducted at a larger Coop store in Sargans (SG), chosen for its significance and customer volume on Saturdays.
• Methodologies: Another expert interview was conducted, and observations in the SCO area of a larger Coop store in Sargans (SG), were made on Saturdays to understand self-checkout operations during peak times.
• Findings: The research revealed that weekly shoppers using self-checkout, especially those utilizing Passabene, did not significantly disrupt operations, even during peak hours. The time spent by bulk shoppers at self-checkout was comparable to that of cash transactions, primarily due to the slower counting process with Passabene.

Findings and Impact

Our comprehensive research revealed that weekly shoppers, particularly those using the Passabene self-scan system, did not significantly impact SCO operations, even at peak times. Interestingly, the duration spent by bulk shoppers at SCOs was found to be comparable to traditional cash transactions, mainly attributed to the slower item counting process with Passabene.

The outcomes of both research phases provided critical insights into the user experience, highlighting specific issues and opportunities for improvement:

Issues at the SCO checkouts:

• Long waiting times due to various reasons.
• Need for improved usability throughout the process.
• High service costs associated with cash acceptance.

Usability enhancements:

• Faster payment capture and processing.
• Reduction in service cases and costs.
• Decrease in interventions by store staff.
• Improvement in checkout utilization and reduction of waiting times.

This meticulous user research was instrumental in refining our understanding of user behaviors and needs, guiding the subsequent design and development phases to enhance the SCO experience at Coop supermarktes.

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Analysis and Modeling

Armed with insights from our user research, we prepared the ground for the design phase. By synthesizing our findings, we aimed to create a user interface that was not only user-friendly but also emphasized accessibility and efficiency. Our initial step involved transforming the preliminary insights—Proto-Problem Statement Maps and Proto-Personas—into validated design artifacts. Utilizing Atomic Research, we distilled our findings into clear, actionable components, aligning closely with our project objectives. This strategic process allowed us to identify and prioritize design elements that directly addressed user needs and pain points.

Persona Development and User Journey Mapping

Critical to our process was the development of detailed personas, achieved through Behavior Pattern Analysis. This analysis helped us understand diverse user characteristics, informing the design of features and functionalities tailored to user needs. Concurrently, User Journey Mapping illuminated the checkout process from a user's perspective, enabling us to pinpoint and address specific areas for improvement.

Competitive Analysis and User Flow Refinement

A thorough competitive analysis further informed our design decisions, highlighting where Coop's self-checkout could stand out against both direct competitors and broader retail market trends. This analysis contributed to the formulation of a "to-be" sitemap, a blueprint for an optimized user flow. This sitemap, iteratively refined based on ongoing usability feedback, outlined a user-centric path through the self-checkout process, ensuring a seamless and intuitive user experience.

In sum, this phase laid the foundation for a design that was deeply informed by user insights, setting the stage for the development of a self-checkout interface that would not only meet but exceed Coop customers' expectations for efficiency and accessibility.

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Design Phase Overview

Entering the Design Phase, our team embarked on defining the project's requirements, drawing from the rich data and insights gained during the analysis and modeling stages. Employing Goal-Directed Design, we crafted Context Scenarios—narrative descriptions that envisage future user interactions with the system. These scenarios were instrumental in offering a deep dive into anticipated system use, providing a solid foundation for identifying functional needs and elements critical to the design.

Building on these Context Scenarios, we detailed Functional Needs and Elements, essential for shaping the user experience. This process allowed us to pinpoint specific user actions and the corresponding interface elements required to support them. A focus on iterative development was key, enabling us to refine these elements continually as we gained further insights into user needs and preferences. This iterative process was vital in ensuring that our design remained agile, responsive to user feedback, and aligned with our goal of creating a user-centric solution.

To illustrate the application of these concepts, we mapped out Key Path Scenarios. These scenarios delineated the core pathways users would navigate within the application, showcasing the integration of identified needs and design elements into a coherent user journey. The evolution of these scenarios underscored our commitment to a design process that adapts and evolves in line with user expectations and emerging insights.

Below is an excerpt from one of our final Key Path Scenarios, highlighting the intricate balance between functional requirements and design elements, encapsulating our vision for a seamless and intuitive user experience.

Design Framework: From Vision to Structure

The Design Framework phase represents a crucial milestone in the design process, as the team shifts its focus to translating the established requirements into a thoughtful and user-centered design structure. This phase began with an intensive Sketching session, where each team member delved into the creative process, drawing from the foundation laid by our Context Scenarios and the projected "to-be" sitemap.

Through sketching, we aimed to breathe life into our vision, creating hand-drawn prototypes of future interfaces. This hands-on approach not only facilitated a free flow of ideas but also grounded our design efforts in the real needs and expectations of users, as captured in the earlier stages of our work. The sketches served as the first tangible step towards realizing a design that is both innovative and intimately aligned with user experiences.

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Following the initial sketching, we engaged in an iterative process to refine our ideas, focusing particularly on overcoming challenges such as those presented by the Product-Look-Up Menu (PLU). This meticulous consolidation and selection phase allowed us to pinpoint and address potential issues early in the design process.

The next critical step involved converging on a unified interaction concept during the Wireframe development stage. This stage was marked by intensive discussions and adjustments, leading to a consensus on the layout, navigation, and interaction principles that would guide our design. We meticulously aligned these elements with the Material Design Standard, ensuring clarity, usability, and consistency across the user interface. This careful planning and alignment with standards ensured our design concepts were not only innovative but also deeply rooted in user needs and project objectives.

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In the absence of specific design guidelines for the Coop SCO-Interface, a moodboard was created to establish a general look-and-feel, focusing on Coop Retail's brand elements such as the orange logo, the 'Für mich und dich' slogan, and visual cues like slate boards and green vegetable crates. Following iterations explored design concepts incorporating round shapes, white elements on a light grey background with black and orange accents, ensuring accessibility compliance. Further enhancements included the introduction of yellow for action indicators and refining the Supercard display. The design process prioritized usability and inclusivity, culminating in an initial design concept and prototype developed collaboratively.

The design aimed to integrate seamlessly into the Coop brand identity while meeting WCAG 'AA' accessibility standards and considering practical usability aspects such as touch target sizes. The iterative process involved constant refinement based on user feedback and evolving requirements, resulting in a cohesive and user-friendly interface ready for usability testing.

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Usability Testing

In this phase of the project, Prototype 1 was developed in accordance with key user scenarios and hypotheses to enhance the SCO-UI interface based on user research insights. Usability testing was conducted in a actual Coop supermarket environment, allowing participants to interact with the prototype while being observed and recorded. Eyetracking technology supplemented participant feedback, providing valuable insights into user comprehension and interface usability.

Prototype Evolution

Prototype 1

The initial phase of usability testing focused on Prototype 1, crafted to enhance the SCO-UI interface drawing on insights from key path scenarios and research findings. Conducted in a real Coop supermarket setting, this phase allowed participants to engage with the prototype in a natural shopping environment. Eyetracking technology complemented this hands-on feedback, offering deeper insights into user interactions and comprehension of the interface.

Feedback from this initial testing phase was invaluable, highlighting areas of the user interface that were well-received alongside those needing refinement. Participants found the overall UI intuitive but expressed preferences for the color scheme of earlier designs. The "Shopping Cart Summary" screen and specific "Start Screen" elements caused some confusion, pointing to areas for improvement. The functionality for adding items like "Plastic Bag" and "Barcode Entry" was praised, despite some challenges with discoverability. Issues with the  Product-Look-Up Menu (PLU) menu's category clarity and the "Grid View" toggle further informed the need for adjustments. Notably, the feedback indicated a desire for a receipt printing option, underscoring the importance of aligning the checkout process with user expectations.

Prototype 2

Armed with these insights, the team refined the design for Prototype 2, focusing on improving PLU navigation and overall interface usability. This iteration saw significant changes, including:

• Highlighting the selected Product-Look-Up Menu (PLU) category more prominently
• Replacing icons with realistic images
• Reducing text and unnecessary icons
• Visualizing multiple selections
• Strengthening the contrast ratio
• Adding tooltips

By eliminating the "Shopping Cart Summary" screen, the information regarding random spot checks is now displayed on the "Checkout" screen. Additionally, the function allowing the Supercard to be scanned until the "Checkout" screen has been modified. Thus, receipts can still be redeemed until shortly before payment.

The refined Prototype 2 was again tested with users at a real Coop SCO cashier to test the revised desing and find further findings about the design and usability.

Prototype 3

Further usability testing led to significant refinements in Prototype 3, notably in the areas of Product Look-Up (PLU) navigation and quantity input. This series of adjustments was driven by a goal to improve usability and ensure visual consistency across the interface. Our team’s dedication to delivering a seamless user experience was evident in these iterative enhancements, which resulted in a design that was not only more intuitive but also closely matched user needs and feedback. Additionally, the design underwent further evaluation against the WCAG "AA" standard, with specific adjustments made to enhance color contrast, thereby ensuring greater accessibility.

In the final stage of testing, we employed rapid prototyping techniques, including A/B testing, focused on the selection of PLU articles. This approach was critical in validating the effectiveness and user-friendliness of the design, ensuring that the final prototype met our high standards for usability.

This detailed approach to usability testing and prototype development reflects a rigorous commitment to optimizing the Coop SCO system's user experience, guided by direct user feedback and a methodical process of iteration and enhancement.

Final Deliverables

Due to project size constraints, it was not feasible to accompany the development process within the given timeframe. However, to ensure a valuable handover, Coop was presented with the results from the Interaction Design phases post-user research.

The final deliverables provided to Coop included:

• A prerecorded presentation showcasing the results from the Interaction Design phases post-user research, facilitating understanding and discussion of the design concepts.
• Figma Design Files containing prototypes and organized components, structured according to Atomic Design principles (Frost, 2013), ensuring clarity and ease of access to design assets.
• UI specifications and documentation, encompassing a Requirements Matrix updated with insights from Usability Tests post-Design Refinement, facilitating the alignment between design decisions and project requirements.

These deliverables were tailored to facilitate a seamless transition from design to development, ensuring that the client had comprehensive resources to support the implementation of the SCO-UI project.

Retrospective and Future Directions

This work emphasizes the importance of a user-centered approach in designing SCO systems. It highlights customers' desires for efficient and independent checkout experiences and emphasizes the need for user-friendly interfaces.

Key findings from user research and usability tests underscore customers' preferences for minimal staff intervention, visually appealing interfaces, and easy navigation. These insights drive the need for designs that minimize disruptions in the checkout process and offer clear visual communication.

The study showcases the effectiveness of the Goal-Directed Design model, emphasizing the importance of understanding user needs and behaviors. Iterative design processes, guided by user feedback, play a crucial role in refining product designs and identifying areas for future innovation.

While certain conditions, like sample size and store selection, influence results, further usability testing with a larger and more diverse sample is recommended for comprehensive validation.

In conclusion, by focusing on intuitive user guidance and optimizing the payment process, SCO systems can enhance customer satisfaction and operational efficiency. Incorporating accessibility into the design process can further strengthen Coop's position as an inclusive and customer-oriented retail group.