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McKinsey Medium Profitability Cost Reduction

Premier Oil

#Energy

Practice this intermediate profitability case interview question from McKinsey in the Energy sector. Includes detailed problem prompt, clarifying questions, structured framework, and expert recommendation. Part of ProHub's 835+ consulting case library.

ProHub Comment

This case tests the candidate's ability to structure cost analysis through fixed/variable cost decomposition, identify root cause drivers of cost inflation, and perform accurate financial calculations under time pressure. The case emphasizes the importance of contextualizing quantitative findings with business risks and strategic considerations.

Estimated Time 26 minutes
Difficulty Medium
Source PeterK
66 / 100
Given there is not much Premier Oil can do to increase sales, the manager wants us to focus on costs. To begin with, what are Premier Oil’s major expenses?

Clarifying Information

  1. The current operational expenses are £50M per year
  2. The current drilling costs are £40M per year
  3. The operational expenses don’t include drilling costs
  4. Current oil production is 200k barrels per day
  5. We can assume 360 days a year
  6. The foreign exchange is $2 for £1
Mock Interview
Interviewer

Given there is not much Premier Oil can do to increase sales, the manager wants us to focus on costs. To begin with, what are Premier Oil's major expenses?

You

Thanks. Before analyzing, I'd like to clarify a few key questions...

Interviewer

Good question. Let me provide some background information...

You

Based on this, I suggest analyzing from these dimensions...

AI Score
Structure Analysis Communication Business Sense Quantitative
Practicing...
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Practice this case with AI Mock Interview

Premier Oil faces increasing maintenance costs on offshore platforms. The case walks through identifying major cost categories (fixed: maintenance, R&D, overhead, energy; variable: labor, supplies, transportation), analyzing maintenance cost drivers (routine vs. reactive), and calculating £26M in potential savings from equipment retrofitting.

Key Insights:

  1. Structure brainstorming into fixed vs. variable costs for clarity and to demonstrate analytical rigor
  2. Break down complex problems into sub-drivers (e.g., maintenance into scheduled vs. emergency, and further into frequency and cost-per-incident drivers)
  3. Calculate answers accurately but also contextualize findings by identifying risks and limitations of assumptions
  4. Proactively ask for missing data rather than making unfounded assumptions
  5. Aim for 4-8 ideas in brainstorming exercises; top performers generate 7-8 structured ideas
  6. Take 30-40 seconds to organize thoughts before presenting, or ideate on-the-fly with clear structure

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