I think the main problem here is Revenue. So, let's just focus on that.
Hypothesis: more stores' competitors nearby the client's presences (following yours)
- How is the overall trend in the past 12 months?
- What is the product mix?
- How has the mix changed in the past 12 months? Specifically for the top 5 products
- How is our goods-sold number compared to the market?
- Where are we right now in terms of the goods sold compared to competitors/market?
- Is there any change in the overall pricing in the past 12 months?
- How is the pricing for the top 5 products change in the past 12 months?
- How is the pricing compared to market practice?
From these 2 factors alone, then we can understand the high-level root cause from quantity or pricing or both, and a little bit of why from the 2nd layer.
You can use that, but you might need to be creative and have to come up with the next structure once you know the high-level issues (example: if pricing is the issue, then you need to ask on why there is change, is the customer price sensitive, etc).
This could be used in a candidate led interview, as it will just appear to be more conversational. You identify the high-level problem, then you go deeper only to the main issue.
- How is the overall fruit market condition in the past 12 months?
- Who are their customers currently (age, income, location)?
- Did the client have any defined segmentation?
- Did the client change direction of segmentation in the past 12 months?
- How is the performance of each segmentation in the past 12 months?
- Product Mix
- What are their top 5 products in the past 12 months? and how much each product allocates to revenue?
- How is the performance of those products in the past 12 months?
- How are the products being priced? Is there any change to this?
- What is the pricing component? Is there any change?
- Who are the competitors? Is there any change in the past 12 months?
- Where is our market share, and how does it change in the past 12 months?
- Is there any new entrant? how has it performed?
- Is there any change to organization int the past 12 months
- Did we change any personnel in the past 12 months?
- How is the process starting from customer searches to checks out? Is there any change to that?
Now, the 2nd structure might appear to be more MECE, but putting this into a conversational kind of interview (candidate led) might sound a bit unnatural.
However, it is extremely recommended using 2nd structure in an interviewer led setup.
Hope that helps!