MANAC Session 10 — Destin Brass Case Study: Overhead Allocation in Practice

Table of Contents

1. Executive Overview
2. Key Learning Objectives
3. Concept Map / Mental Model
4. Case Setup & Base Data
5. Method 1 — Plantwide Rate (DL-Cost Base)
6. Method 2 — Two-Stage Allocation
7. Method 3 — Activity-Based Costing (ABC)
8. Method Comparison Table
9. Strategic Interpretation
10. Classic Brass Inc. — ABC Implementation Example
11. Frameworks & Models
12. Terminology & Definitions
13. Critical Insights & Professor Takeaways
14. Connections
15. Practical Application
16. Potential Exam Questions
17. Revision Sheet
18. Action Items / Further Reading
19. Final Summary

1. Executive Overview

This session uses the Destiny Brass Products Company case to show why overhead allocation is a strategic decision, not just an accounting technique.

The core message: when overhead is large and products consume activities very differently, simple costing systems can systematically misprice products, distort profitability, and push managers into the wrong competitive responses — e.g., matching a competitor's price cut without first diagnosing whether your own cost model is wrong.

The Arc of the Session

1. Reconstruct base data (volumes, labor, machine hours, overhead pool) from the case exhibits.
2. Compute costs under three approaches:
   • Method 1: Traditional plantwide rate (OH on direct labor cost)
   • Method 2: Two-stage allocation (materials % + machine-hour rate; setup treated separately)
   • Method 3: ABC (multiple drivers — transactions, shipments, engineering %, machine-hour share)
3. Read the full margin comparison table — the key strategic output.
4. Interpret: why a competitor can price lower; why "35% gross margin for every product" is a dangerous target; and why ABC is "harder to object to."

Big-Picture Takeaway

If you don't understand the drivers of overhead, your profit numbers become "storytelling numbers." Good managers treat costing as a diagnostic tool to uncover complexity, redesign processes, and make smarter pricing and product decisions — not as a mechanical compliance exercise.

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2. Key Learning Objectives

By the end of this session, you should be able to:

1. Reconstruct product costs under three different overhead allocation systems.
2. Explain why overhead allocation affects strategy, not just accounting statements.
3. Diagnose when a competitor's lower price could come from lower prime costs, different product mix, or simply better overhead logic (less cross-subsidy).
4. Identify complexity signals — runs, shipments, transactions, engineering effort — and link them to overhead causality.
5. Read and interpret a full margin comparison table across methods.
6. Evaluate the trade-off: improved accuracy of ABC vs its implementation and maintenance cost.
7. Describe a 5-step ABC implementation using the Classic Brass example.
8. Translate costing outputs into managerial decisions: pricing, product continuation, process improvement, incentive design.

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3. Concept Map / Mental Model

Starting point: Competitive pressure (price cut)

• → Need accurate cost diagnosis before deciding to match, hold, or redesign

Cost structure

• Prime costs (DM + DL) are traceable
• Overhead is indirect — allocation choice determines the profitability story

Overhead allocation ladder (accuracy vs cost)

Complexity

• More setups / runs / shipments / transactions / engineering changes → higher overhead consumption → higher true cost
• If cost changes drastically across methods → complexity is concentrated in that product

The key diagnostic output: margin comparison table

• Read it across methods for each product
• Margin improvements as method improves = that product was being over-allocated
• Margin collapses as method improves = that product was being under-allocated (the complexity-heavy one)

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4. Case Setup & Base Data

4.1 The Managerial Question

The case is not about calculating a number for its own sake. The real problem:

• A competitor cuts price on pumps.
• Should we match? Hold price? Redesign costs?
• First move: diagnose your cost structure and cost attribution before reacting.

4.2 Why "Selling Price" Is Not the Main Lever

Price is external (market, competitor, customer willingness-to-pay). The controllable lever is cost, especially overhead when overhead is large. If allocation is sloppy, you punish the wrong product and reward the wrong manager.

4.3 The "35% Gross Margin for Every Product" Target — Why It Can Mislead

A uniform gross margin target feels neat but is strategically wrong if:

• Product-level costs are distorted by a bad allocation system
• Overhead is cross-subsidizing one product line with another's costs
• Product complexity differs sharply

4.4 Exhibit Map

4.5 Production Volumes + Complexity Markers (Exhibit 1)

Key observation: Flow controllers have the lowest volume but the highest complexity across every marker. This is the classic environment where a single plantwide rate will be systematically misleading.

4.6 Direct Materials per Unit (Exhibit 2)

Total DM (monthly): $458,000 | Labor rate: $16/hour (including benefits)

4.7 Run Direct Labor Hours & Cost

4.8 Setup Labor Hours & Cost

Setup hours per run: Valves 8 hr, Pumps 8 hr, Flow controllers 12 hr

Setup is a strong complexity driver. Low-volume/high-variety products consume more setups relative to their unit volume.

4.9 Machine-Hours (Exhibit 2)

4.10 Total Overhead Pool (Exhibit 3)

4.11 Selling Prices (Actual)

⚠️ Note: Some notes show Valves at $57.78 — the professor's class notes show $57.26. Use $57.26.

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5. Method 1 — Plantwide Rate (DL-Cost Base)

5.1 Logic

One plantwide overhead rate applied using run direct labor cost as the single allocation base. Simple; dangerous when overhead is large and products differ in complexity.

5.2 Plantwide Overhead Rate

• Allocation base = total run DL cost = $155,600
• OH pool (including setup) = $682,688
• OH rate = 682,688 / 155,600 ≈ 4.39 × direct labor cost (439%)

OH is 4.39× the run DL cost — a strong signal that DL is no longer a good proxy for overhead consumption.

5.3 Unit Costs Under Method 1

5.4 What Method 1 Hides

Plantwide DL-based allocation assumes products that use more DL cost "cause" more overhead. But complexity does not scale with DL. Flow controllers have low volume but high transactions, shipments, and runs — none of which are captured here.

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6. Method 2 — Two-Stage Allocation

6.1 Why Method 2 Is a Step Up

Instead of a single driver, it uses more causal mapping:

• Material-related overhead ↔ material dollars
• Machine-related overhead ↔ machine-hours
• Setup tracked as its own direct cost layer

Still not full ABC, but improves realism.

6.2 Overhead Split into Two Pools

Pool 1 — Material-Related OH

• Rate: 220,000 / 458,000 = ≈48% of materials

Pool 2 — Machine-Hour Related OH

• Rate: 460,000 / 10,800 = ≈$42.59 per MH

6.3 Setup as Direct Layer

Setup per unit explodes for flow controllers — high setups relative to their volume.

6.4 Unit Costs Under Method 2

6.5 What Shifts and Why

Flow controllers' cost drops from Method 1 ($56.50 → $47.96) because their machine-hours per unit is low (0.20), so the machine-hour pool charges them less. But the massive transaction and shipping burden is still not captured — setup alone ($0.48) barely reflects the full complexity cost.

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7. Method 3 — Activity-Based Costing (ABC)

7.1 Why ABC Is "Harder to Object To"

ABC maps overhead to activities and allocates based on actual activity consumption. When drivers are credible, the numbers feel fair and defensible:

"If you cause more transactions, shipments, and engineering changes, you should absorb more of those costs."

7.2 Activity Drivers and Pool Rates

1) Receiving + Materials Handling — Driver: Transactions

• Pool: $220,000 | Rate: 220,000 / 129 = $1,705.43/transaction

Flow controllers consume massive transaction effort per unit — this is the "shock" result.

2) Packing & Shipping — Driver: Shipments

• Pool: $60,000 | Rate: 60,000 / 30 = $2,000/shipment

3) Engineering — Driver: Work-Order Share (Exhibit 4)

4) Maintenance — Driver: Machine-Hour Share

• Pool: $30,000

5) Depreciation — Driver: Machine-Hours

• Pool: $270,000 | Rate: 270,000 / 10,800 = $25/MH

6) Setup — Direct Layer

7.3 ABC Unit Cost Build-Up

✅ These figures are from the professor's class handwritten notes (Page-1). They are the authoritative numbers for the Destin Brass case.

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8. Method Comparison Table

8.1 Unit Costs Across All Three Methods

8.2 Cost Delta vs Method 1

Flow controllers swing +$44 under ABC vs the plantwide rate. That magnitude is a direct signal of complexity and cross-subsidization.

8.3 Gross Margin at Actual Selling Prices — All Three Methods

This table is the single most important output of the Destin Brass case. Read it carefully.

Selling prices used: Valves $57.26, Pumps $81.26, Flow controllers $97.007

8.4 Strategic Reading of the Margin Table

Flow controllers: Appear most profitable under Method 2 (51%) and comfortably profitable under Method 1 (42%) — but are loss-making under ABC (−4%). This is cross-subsidization in its most dangerous form. The more accurately you measure, the worse this product looks.

Pumps: Margin improves from 22% (Method 1) to 40% (ABC). They were being over-allocated overhead they did not cause — penalised by the system for being a high-volume product.

Valves: Stable at ~35% across all methods. Valves is not the source of distortion — it is the "neutral" product in this case.

The competitive implication: A competitor pricing pumps aggressively may not be sacrificing margin — they may simply have a better cost system that correctly tells them pumps carry less overhead burden than the Destiny Brass traditional system claims.

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9. Strategic Interpretation

9.1 What a Large Cost Swing Tells You

If a product's cost changes significantly when you change the allocation method, it is the complexity-heavy product. In this case, flow controllers shift from profitable (traditional) to loss-making (ABC), which means they are consuming:

• More receiving/handling (high transactions)
• More shipping (many small shipments)
• More engineering effort (50% of work-order share with only 4,000 units)
• More setups relative to their volume

9.2 How to Respond to a Competitor's Price Cut

The managerial sequence taught in class:

1. Do not immediately match the price cut.
2. First ask: Why can they price lower?
   • Are they sacrificing margin?
   • Are their prime costs structurally lower?
   • Is their overhead allocation more accurate — less internal cross-subsidy?
3. Revisit your costing logic. Identify where you are over/under-costing.
4. Decide a strategy:
   • Raise price / change terms for complex products (flow controllers)
   • Redesign processes to reduce complexity costs (batch shipments, reduce transactions)
   • Simplify the offering
   • Exit unprofitable segments

9.3 Incentives and Internal Dysfunction

If traditional costing makes flow controllers look profitable at 42% margin:

• Managers will push flow controllers aggressively (the numbers tell them to)
• The business is actually destroying value at every unit sold
• High-volume teams get punished ("your product has high overhead") when they are not the overhead cause

The professor calls this internal disability — the costing system creates dysfunction from within.

9.4 The Monopoly Implication

If flow controllers are truly costly (high complexity) and the firm has pricing power (monopoly or strong differentiation), the right move might be raising prices, not cutting them. Traditional costing hides that opportunity by making the product look cheap and profitable.

9.5 When ABC Is Worth It vs Not

Use ABC when:

• Overhead is large relative to prime costs
• Product/process variety is high
• Complexity drivers differ materially
• Pricing and mix decisions are sensitive to cost accuracy

Simplify when:

• Operations are homogeneous
• Overhead is small relative to prime costs
• Product variety is minimal
• Cost accuracy doesn't materially change decisions

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10. Classic Brass Inc. — ABC Implementation Example

This example from the professor's slides illustrates the full 5-step ABC implementation, and extends the analysis to customer profitability — something traditional systems never do.

10.1 Context

Classic Brass Inc. makes two product lines for luxury yachts:

• Standard stanchions — high volume, standardized
• Custom compass housings — low volume, custom-designed per order

The company reported its first-ever loss of $1,250 despite what appeared to be reasonable revenue. Traditional costing (single plantwide rate on machine hours) was hiding the real economics.

10.2 Step 1 — Define Activities, Cost Pools, and Activity Measures

Classic Brass selected five activity cost pools:

The "Other" pool captures organisation-sustaining costs (factory security, plant manager's office) and idle capacity costs. These are excluded from product costs in ABC — products are charged only for resources they actually consume.

10.3 Step 2 — Assign Overhead Costs to Activity Cost Pools (First-Stage Allocation)

Overhead costs from the general ledger are distributed to the five activity pools based on interviews with departmental staff — asking what percentage of their time/resources is consumed by each activity.

For example: indirect factory workers allocate 20% of their time to customer orders, 40% to design changes, 20% to order size, 10% to customer relations, and 5% to "other."

10.4 Step 3 — Calculate Activity Rates

Given Classic Brass's expected activity levels:

• 1,000 customer orders
• 400 design changes
• 20,000 machine-hours
• 250 active customers

Activity rate = Total pool cost ÷ Total activity volume

10.5 Step 4 — Assign Overhead to Products

Standard stanchions:

• 30,000 units ordered in 600 separate orders
• 0.583 MH per unit → 17,500 total MH
• No design resources required

Custom compass housings:

• 1,250 units produced (400 separate orders, one design per order)
• 2 MH per unit → 2,500 total MH
• 400 design changes (one per order)

Custom compass housings consume a disproportionate share of customer orders and design changes relative to their unit volume — the same complexity pattern as flow controllers in Destin Brass.

10.6 Step 5 — Prepare Management Reports

ABC produces two types of reports unavailable under traditional systems:

Product profitability: Which products are truly profitable after correctly tracing all activity costs?

Customer profitability: Which customers are profitable? The same customer may order a mix of standard and custom products, may place many small orders (high transaction cost), and may require high levels of relationship management.

Example — Windward Yachts as a customer:

• 3 orders: 2 for 150 standard stanchions each, 1 for a custom compass housing
• 177 total machine-hours
• 1 of 250 active customers

Classic Brass can now compute the full cost of serving Windward Yachts and assess whether the relationship is profitable.

10.7 Key Lesson from Classic Brass

The company was reporting a loss not because revenue was too low but because its costing system was telling it the wrong story. Custom compass housings were consuming far more customer order, design change, and customer relation resources than standard stanchions — but traditional MH-based allocation distributed costs proportionally to machine time, making custom products look cheaper than they were.

The fix: Raise prices on custom products, renegotiate high-maintenance customer relationships, or redesign the custom product process to reduce transaction intensity.

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11. Frameworks & Models

Framework 1: Overhead Allocation Methods Ladder

Plantwide rate → Two-stage pools → ABC

Framework 2: Complexity Diagnostic

"If cost changes a lot across methods → the product likely drives complexity."

1. Compute costs under simple and richer methods.
2. Compare product-level deltas.
3. Investigate drivers for the product with the largest swing (setups, shipments, transactions, engineering changes).
4. That investigation tells you where process improvement and pricing discipline matter most.

Framework 3: Price Cut Response Decision Logic

Observe competitor price cut
        ↓
Diagnose *why* they can do it
(lower prime costs? better costing system? sacrificing margin?)
        ↓
Validate your own cost model
        ↓
Decide: match / hold / redesign / re-segment / exit

Framework 4: ABC 5-Step Implementation

Define activities → Assign costs to pools → Calculate rates → Assign to products → Prepare reports

The "Other" pool (organisation-sustaining + idle capacity) is defined at Step 1 and excluded from product assignment at Step 4.

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12. Terminology & Definitions

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13. Critical Insights & Professor Takeaways

• Overhead is not "free." It represents real resource consumption; allocation is an attempt to trace causality.
• Don't match price cuts blindly. First diagnose whether your cost model is distorting your strategy.
• Uniform margin targets can be dangerous when cost attribution is noisy — a 42% margin for flow controllers is a fiction.
• ABC is harder to object to because it ties costs to activity consumption. If the drivers are credible, managers cannot credibly dispute the allocation.
• Large cost swings across methods are signals, not nuisances — signals of complexity and cross-subsidy. The swing itself tells you where to investigate.
• Costing systems shape incentives. Bad costing creates internal dysfunction: managers optimize the wrong products and processes.
• ABC can extend to customer profitability — the same logic that traces costs to products can trace costs to customers, revealing which relationships destroy value.

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14. Connections

14.1 Interdisciplinary Connections

14.2 Connection to Previous Session

• Session 9 built the theoretical foundation for ABC — cost objects, overhead allocation logic, five levels of activity, transaction vs duration drivers, and the three ways ABC differs from traditional costing.
• This session applies all of that theory to real case data. The AEC Engineering example from Session 9 is the same logical structure as Destin Brass — just simpler.

→ Session 9 Notes — ABC Theory & Foundations

14.3 Bridge to Session 12 — CVP Analysis

Session 12 moves from "what does each product cost?" to "how does cost structure translate into profit at different volumes?" The contribution margin and fixed-cost logic in CVP is the next step after getting product costs right — you can't do meaningful break-even analysis if your product costs are distorted by a bad allocation system.

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15. Practical Application

Manager Perspective

• Identify which products are complexity-heavy and ask: should we price them higher? Can we redesign operations to lower shipments/transactions/setups? Should we simplify SKUs or customer commitments?
• Use the margin comparison table as a diagnostic, not as truth. Ask: which method reflects reality most closely for our product mix?

Consultant Perspective

• Map overhead pools → hypothesize drivers → test causality → quantify cross-subsidy → identify "value-destroying growth."
• Build a decision case: keep product with price increase + operational redesign, or exit.
• Extend to customer profitability: use ABC to identify which customers generate cost disproportionate to revenue.

Placement / Interview Relevance

Prompts this session prepares you for:

• "Why can product-level profitability be misleading?"
• "When is ABC necessary?"
• "How would you respond to a competitor price cut using cost analysis?"
• "A business unit's margin looks strong — how do you validate it?"

Common Organizational Mistakes

• Using one-rate overhead in a high-automation, high-SKU environment.
• Treating accounting product margins as "truth" rather than as model outputs.
• Incentivizing product managers based on distorted gross margins.
• Reacting to competitive price cuts without first diagnosing whether internal costing is the problem.

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16. Potential Exam Questions

A) Conceptual

Q1. Explain why a plantwide overhead rate can distort product costs when overhead is high.
Include: Overhead causality, cross-subsidy, heterogeneity, DL no longer a good proxy.

Q2. Define ABC and explain why it is "harder to object to."
Include: Activities, drivers, cost pools, causality, defensibility.

Q3. What are organisation-sustaining costs? How are they treated in ABC?
Include: Definition, why excluded from products, examples.

B) Application / Numerical

Q4. Given volumes, DL, and total overhead, compute a plantwide OH rate and unit costs under Method 1.
Include: Base selection, OH/unit calculation, total unit cost.

Q5. Split overhead into material-related and machine-related pools and compute costs under Method 2.
Include: Material % rate, machine-hour rate, setup as direct layer.

Q6. Using the Destin Brass data, compute ABC overhead and total cost for one product.
Include: All five pools, activity rates, per-unit computation, ABC total cost.

C) Case-Based / Analysis

Q7. A competitor reduces price for one product line. Outline a managerial response using the logic of this session.
Include: Diagnose why competitor can do it, validate costing, identify complexity drivers, decide match vs redesign vs exit.

Q8. A product's cost jumps dramatically under ABC versus traditional costing. What does that indicate and what actions follow?
Include: Complexity diagnosis, pricing, process redesign, SKU simplification.

Q9. "ABC provides better costs, but may not be worth it." Discuss.
Include: Benefits vs measurement cost, organisational fit, materiality of distortion, decision use-cases.

Common Mistakes to Avoid

• Writing generic pros/cons without linking to specific drivers (transactions/shipments/engineering).
• Forgetting to connect costing results to managerial decisions.
• Ignoring the margin comparison table and focusing only on unit cost calculations.

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17. Revision Sheet

High-Yield Ideas

• Overhead allocation = strategic lens, not clerical task.
• If overhead is large and products differ → plantwide rates mislead.
• Cost swing across methods = complexity signal.
• The margin table tells the strategic story — read it across methods, not just within one.

Key Numbers (From Class — Authoritative)

Key complexity drivers: Runs/setups · Transactions (components) · Shipments · Engineering work orders · Machine-hours

Method Snapshots

ABC Unit Costs — Authoritative Figures (Professor's Class Notes)

Gross Margin Comparison — Must Memorise

Memory Triggers

• "Overhead is somebody allocates to you."
• "Don't match price cuts before you diagnose costs."
• "ABC is harder to object to."
• "Large cost swing = complexity signal."
• "Organisation-sustaining costs → excluded from products."

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18. Action Items / Further Reading

• Revisit: Session 9 ABC theory — the five activity levels and three ways ABC differs from traditional costing underpin everything in this session.
• Practice: Build the full Destin Brass cost computation in Excel under all three methods, then verify your margin table against Section 8.3.
• Explore: Customer profitability analysis as an extension of ABC — the Classic Brass Windward Yachts example is a good starting point.
• Preview: Session 12 — once you know what products truly cost, CVP analysis determines how cost structure translates into profit at different volumes.

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19. Final Summary

In high-overhead, high-variety environments, the costing system can manufacture profitability stories. Flow controllers looked like a 42–51% margin business under traditional methods — they are actually loss-making under ABC.

ABC and activity drivers reveal the real economics: complexity is costly, and strategy should respond to that reality. The margin comparison table is not a number-crunching exercise — it is a diagnostic that tells you which products to price up, which processes to redesign, and which competitors to take seriously.

If you don't understand the drivers of overhead, your profit numbers become "storytelling numbers."

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