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Tesco wanted to review their Overstock Investigation (OSI) app and the store process. They believed:

  1. From the 3.8 million products scanned monthly for this process, 75% investigations done by colleagues in store added no value as they were known overstocks.

  2. Stickering products that were overstocked added little value for colleagues or the store managers and could potentially be removed.

I worked as Senior User Experience Designer, alongside the product, engineering, analytics, business and transformation teams, collectively known as the OSI Team. Our target audience were Tesco store employees (also known as colleagues) using the OSI app and their managers.

My contribution was to understand the problem space through store visits, define the problem space, set achievable goals and design a proof of concept that could be created with the engineering team and be taken into a 5 store trial to learn from.

One challenge we faced was a shortage of lorry drivers in UK, due to Brexit. This meant the number of deliveries being made were less and as a result overstock was not a major problem in stores while the research was happening. We tackled this by also including analytics about the usage of the app before the lorry driver shortage.

Tesco OSI old vs new.jpg



We started with a kick off meeting where the teams introduced themselves and we spoke about each individual’s role, responsibilities and time they were committing. The product and business teams introduced the problem space. As a team we decided to go for a store visit to understand the problem in context. It also allowed us to shadow and speak to colleagues while they performed the process. This helped the OSI team define the problems statements, goals and the scope of the project.


One challenge I faced was that the Product team was working with the Research & Design team for the first time and had little understanding on how our team approached problems using design thinking. To facilitate this, I created a customised visual representation of the Double Diamond and explained to the team the approach we would be taking, the timelines associated and when we would be reaching our milestones. Before every meeting, I would recap where we are in the process and what were our next steps. This helped the teams embed themselves in the new process. It also helped our team to get buy in to new ways of working.


I set up store visits for all store formats at Tesco. In all stores, I interviewed relevant team managers and colleagues from multiple departments. Where possible, I shadowed and observed colleagues completing the OSI process.

The research helped to refine our problem statements and goals. It further helped us to understand the mindset of two distinct type of users who performed the OSI process. After research, I mapped the As-is journey of the process and highlighted the differences by department and format. My next step was to analyse what were the main themes that we needed to solve in the upcoming workshop I had scheduled.

The slides below show more detail about the research and post research outputs.


An in-person workshop was set up to ideate the most important themes agreed with the OSI team. Each theme went through a round of crazy 8. The crazy 8 ideas were categized and the team voted on the best ideas. The OSI team worked together in drafting the proposed journey for the ideas with the most votes.

One challenge we faced in the workshop was what is considered a “valuable change”? Was it monetary value of a product, time/effort of a colleague or what led to a change in order? Different teams initially had different perspectives. I directed the conversation and we decided to create a cost Vs. impact analysis chart. This chart helped the team evaluate and then come to an informed decision on what they collectively considered a “valuable change”. In this instance it was what led to a “change in order”.

Below are pictures from the workshop and a proposed process flow chart (created in collaboration with the product team after the workshop).


Keeping in mind the proposed process from the workshop, I designed the high level site map of the app and lo-fidelity wireframes. I walked the team through the designs and we went through one final round of iteration before the journeys were presented to store colleagues and managers.

While the designs were still being created another challenge we faced was that the engineering team was ready to start working. They had been part of the meetings and discussions so were up to speed with the concept. We collaboratively decided to start build on the entry screens and the back end of how lists would be created (neither of those tasks needed the final designs).

In research, the change in process and the app was well received. However, there were a few types of products that the colleagues wanted to be tackled earlier in the process. We reconsidered when those products should be introduced in the journey. Keeping all the insights in mind, the hi-fidelity designs were created (see slides below).


The designs were handed over to the engineering team. When I resigned from Tesco, the engineering team was working to build the proof of concept that was expected to be piloted in 5 stores. I was part of the sprint stand ups, refinement sessions and demos.