Operations Cases: Supply Chain, Process, and Efficiency

Operations cases test your ability to diagnose and fix inefficiencies in how a company produces and delivers its products or services. Based on our analysis of 800+ consulting case prompts, operations questions appear in roughly 10-15% of interviews — and that share rises to 25%+ at firms with dedicated operations practices like McKinsey Operations, BCG’s Operations team, and Kearney. Unlike strategy cases that ask “what should we do,” operations cases ask “how can we do it better, faster, or cheaper.”

Types of Operations Cases

flowchart LR
    A[Operations] --- B[Supply Chain] & C[Process] & D[Capacity]
    
    B --- B1[Sourcing] & B2[Production] & B3[Inventory] & B4[Logistics]
    C --- C1[Map Process] & C2[Find Bottleneck] & C3[Root Cause]
    D --- D1[Utilization] & D2[Expand vs Optimize]

    style A fill:#1e3a5f,stroke:#0d1f33,color:#fff
    style B fill:#2563eb,stroke:#1e40af,color:#fff
    style C fill:#2563eb,stroke:#1e40af,color:#fff
    style D fill:#2563eb,stroke:#1e40af,color:#fff

Operations cases fall into three main categories, each requiring a different analytical lens. Recognizing the type early helps you select the right framework and ask sharper clarifying questions.

Case Type	Core Question	Typical Industries	Key Metrics
Supply chain optimization	How can we reduce cost or improve reliability across the value chain?	Manufacturing, Retail, Consumer Goods	Inventory turns, fill rate, lead time
Process improvement	How can we increase throughput or reduce defects?	Manufacturing, Healthcare, Financial Services	Cycle time, yield, OEE
Capacity planning	Should we expand, and if so, how?	Energy, Manufacturing, Technology	Utilization rate, ROI, payback period

Supply Chain Optimization

Supply chain cases focus on the flow of materials and information from suppliers to end customers. The goal is typically to reduce cost, improve speed, or increase reliability. A structured approach examines each link in the chain:

1. Sourcing and procurement: Are raw materials being purchased at competitive prices? Could consolidating suppliers save 5-15% on procurement spend? In our experience, procurement optimization is the fastest lever — savings can be realized within 3-6 months.
2. Manufacturing/production: Is the production process efficient? Where are the bottlenecks? What is the defect rate?
3. Warehousing and inventory: Are inventory levels optimized? Excess inventory ties up cash; too little causes stockouts. Target inventory turns vary by industry — grocery operates at 15-25 turns per year, while industrial goods may be 4-8.
4. Distribution and logistics: Is the distribution network designed for the right trade-off between cost and speed? Could route optimization reduce transportation costs by 10-20%?

Process Improvement

Process improvement cases ask you to increase output quality, speed, or both — without proportionally increasing costs. These cases frequently appear in manufacturing and healthcare contexts.

The diagnostic approach follows four steps:

1. Map the current process end-to-end, noting each step’s duration and output
2. Identify bottlenecks — the step that constrains overall throughput
3. Analyze root causes using tools like the “5 Whys” or fishbone diagram
4. Propose solutions that address root causes, not just symptoms

A common interview scenario: “A factory’s output has dropped 20% over the past quarter. What would you investigate?” Strong candidates map the production flow, isolate the bottleneck step, and quantify the impact before proposing fixes.

Capacity Planning

Capacity planning cases involve deciding whether to expand production capacity, and if so, how. The trade-off is between meeting growing demand and avoiding overinvestment. Key considerations include:

• Current utilization rate (above 85% typically signals the need for expansion)
• Demand forecast reliability (how confident are the growth projections?)
• Build vs. lease vs. outsource analysis
• Capital expenditure and payback period (typically 3-7 years for major expansions)

Three Essential Frameworks

Value Chain Analysis

Value chain analysis is a systematic method for mapping every step from raw material inputs to customer delivery, identifying where value is created and where waste accumulates. For operations cases, this means:

1. List each step in the process (procurement, manufacturing, assembly, quality check, packaging, distribution)
2. Record the time, cost, and defect rate at each step
3. Calculate the percentage of total cost and time each step represents
4. Identify steps with disproportionate cost or time — these are your priority targets

Based on our work with case data, the most impactful improvements often come from the 2-3 steps that account for 60-70% of total cost or time.

Lean Operations (Seven Wastes)

Lean operations, originally developed in Toyota’s production system, identifies seven categories of waste to eliminate. This framework is especially powerful in process improvement cases.

Waste Type	Definition	Example	Improvement Lever
Overproduction	Making more than needed	Building inventory “just in case”	Pull-based production, demand forecasting
Waiting	Idle time between process steps	Materials queued for quality inspection	Parallel processing, buffer reduction
Transportation	Unnecessary movement of materials	Parts shipped between distant warehouses	Facility layout optimization
Over-processing	Work beyond customer requirements	Polishing components that are hidden	Spec review, value engineering
Inventory	Excess raw materials or finished goods	90 days of safety stock when 30 is sufficient	JIT delivery, demand sensing
Motion	Unnecessary movement of people	Workers walking across factory floor for tools	Workstation design, 5S methodology
Defects	Output that fails quality standards	8% reject rate on assembly line	Root cause analysis, poka-yoke (error-proofing)

In our experience, the highest-impact waste category in most manufacturing settings is waiting and inventory — together they often account for 40-50% of total cycle time.

Theory of Constraints (TOC)

Theory of Constraints is a management methodology that focuses on finding and improving the single biggest bottleneck in a system. The core principle: improving a non-bottleneck step does nothing for overall throughput.

The five-step TOC process:

1. Identify the constraint (the step with lowest capacity or highest utilization)
2. Exploit the constraint (maximize output from the bottleneck without additional investment)
3. Subordinate all other steps to the constraint (align upstream and downstream to the bottleneck’s pace)
4. Elevate the constraint (invest to increase bottleneck capacity)
5. Repeat — once a bottleneck is resolved, a new one emerges

For example, if a manufacturing line has five stations and Station 3 can only process 80 units per hour while all others handle 120+, Station 3 is the constraint. Investing in Stations 1-2 or 4-5 will not increase total output.

Key Metrics Every Candidate Should Know

Metric	Formula	What It Tells You	Good Benchmark
OEE (Overall Equipment Effectiveness)	Availability x Performance x Quality	How well equipment is being used	World-class: 85%+
Cycle time	Total time from start to finish of one unit	Process speed	Varies by industry
Throughput	Units produced per time period	Production capacity	Compare to demand
Yield	Good units / Total units produced	Quality rate	95%+ in most manufacturing
Inventory turns	COGS / Average inventory	Capital efficiency	Grocery: 15-25x; Industrial: 4-8x
Fill rate	Orders shipped complete / Total orders	Customer service level	95%+ is standard

Structuring Your Operations Case Answer

When you receive an operations case, follow this sequence:

1. Clarify the objective. Is the goal to reduce cost, increase output, improve quality, or some combination? Quantify the target if possible (“reduce costs by 15%”).
2. Map the process. Ask for a description of the end-to-end operation. Draw it out if possible.
3. Identify the bottleneck. Which step has the lowest throughput, highest cost, or worst quality?
4. Diagnose root causes. Why does the bottleneck exist? Is it equipment, labor, process design, or external factors?
5. Propose solutions. Prioritize by impact and feasibility. Quantify expected improvement.
6. Address implementation. Timeline, cost, risks, and how to measure success.

Practice this structure with operations cases in our case library. For related frameworks, see our guide on profitability cases, which often overlap with operations when cost reduction is the goal.

Key Takeaways

• Operations cases appear in 10-15% of consulting interviews overall, but 25%+ at operations-focused firms — a high-value preparation area
• Recognize the case type early (supply chain, process improvement, or capacity planning) to select the right framework
• The Lean Seven Wastes framework is especially versatile: waiting and inventory waste alone account for 40-50% of cycle time in most manufacturing settings
• Theory of Constraints teaches a critical principle: improving a non-bottleneck step adds zero value to overall throughput
• Always quantify the bottleneck’s impact before proposing solutions — “Station 3 runs at 80 units/hour vs. 120 for other stations, limiting total output by 33%”
• Memorize the key metrics table (OEE, cycle time, throughput, yield, inventory turns) — interviewers expect you to use these terms fluently

Ready to practice? Browse operations cases in our case library for hands-on scenarios, or test your diagnostic skills in a timed AI Mock Interview that simulates real operations case conversations.