Chapter 6: Inventories: Costing, Cost Flow Assumptions, Measurement, and Errors

Comprehensive Study Guide (with extra foundational scaffolding)

Learning Objectives Map

Relevant CPA competencies named in your text: 1.1.2 (evaluating the basis of financial reporting, methods of measurement), 1.1.3 (evaluating reporting systems/data requirements, accounting information systems), 1.2.1 (developing/evaluating accounting policies, ethical professional judgment), 1.2.2 (evaluating treatment for routine transactions, specifically inventories and changes in accounting policies/estimates and errors), 1.3.2 (preparing routine note disclosure). These tell you inventory is treated as a Level A competency area for routine transactions, i.e., something you're expected to handle with high proficiency, not just recognize.

Decision Flowcharts & Logic Trees

LOCM cascade: finished goods first, raw materials only if triggered

[Tutor-added] Decision logic derived entirely from Part E of your source. No new rules introduced.

flowchart TD
    START["Period end.<br/>Test inventory for writedown."]
    START --> FG{"Is the FINISHED PRODUCT impaired?<br/>Is NRV below cost?"}

    FG -->|"NO — finished product still<br/>expected to sell above total cost"| STOP["STOP.<br/>NO writedown on finished goods.<br/>NO writedown on raw materials,<br/>even if input prices have collapsed."]
    FG -->|"YES — NRV is below cost"| WD["Write finished goods DOWN to NRV.<br/>Never write UP above cost."]

    WD --> RM{"Now assess RAW MATERIALS<br/>and work in progress"}
    RM -->|"Use REPLACEMENT COST —<br/>more readily and reliably<br/>observable than tracing NRV<br/>through to finished product"| RMWD["Write raw materials down to<br/>replacement cost if it is<br/>below carrying value"]

    STOP --> NOTE["Gate 1 controls Gate 2.<br/>Testing raw materials in isolation<br/>is the fatal error."]

Cost flow assumption selection

[Tutor-added] Decision logic derived entirely from Parts C and D of your source.

flowchart TD
    START["Which costing approach<br/>applies to this inventory?"]
    START --> Q1{"Are the goods individually<br/>distinguishable and NOT<br/>ordinarily interchangeable?"}

    Q1 -->|"Yes — e.g. custom equipment,<br/>serialized high-value items"| SPEC["SPECIFIC IDENTIFICATION<br/>Track the actual cost<br/>of each actual unit"]
    Q1 -->|"No — interchangeable goods"| Q2{"Which cost formula?"}

    Q2 -->|"First-in, first-out"| FIFO["FIFO<br/>Permitted under IFRS and ASPE"]
    Q2 -->|"Weighted average"| WAC["WEIGHTED AVERAGE COST<br/>Permitted under IFRS and ASPE"]
    Q2 -->|"Last-in, first-out"| LIFO["LIFO<br/>PROHIBITED in Canada<br/>under IFRS and ASPE"]

    FIFO --> SYS1{"Periodic or perpetual system?"}
    WAC --> SYS2{"Periodic or perpetual system?"}

    SYS1 -->|"Either"| SAME["FIFO gives IDENTICAL results<br/>under both systems"]
    SYS2 -->|"Periodic"| WACP["Weighted average computed<br/>ONCE at period end"]
    SYS2 -->|"Perpetual"| WACM["MOVING AVERAGE —<br/>average recomputed after<br/>EVERY purchase"]

Exhibit 6-6 reconstructed: Allocating cost of goods available for sale

Exhibit number and full content preserved exactly; schematic redrawn as Mermaid. [Visual upgrade, substitution]

flowchart LR
    BI["Beginning inventory"]
    P["+ Purchases<br/>or cost of production"]
    COGAS["= COST OF GOODS<br/>AVAILABLE FOR SALE<br/>One single pool of dollars"]
    SPLIT{"Allocate the pool<br/>using a cost flow<br/>assumption"}
    COGS["COST OF GOODS SOLD<br/>Income statement"]
    EI["ENDING INVENTORY<br/>Balance sheet"]

    BI --> COGAS
    P --> COGAS
    COGAS --> SPLIT
    SPLIT -->|"Goods that left"| COGS
    SPLIT -->|"Goods still on hand"| EI

Part 0: Foundations Refresher

(This part is my addition, built to give you the grounding your syllabus assumes you already have from introductory accounting. If you're comfortable with basic COGS mechanics and debits/credits, skim this and go to Part A.)

What is inventory, really?

Inventory: an asset, goods a company holds for the purpose of selling them (or, for a manufacturer, the raw materials and partially-finished goods that will eventually become something sold).

Three sub-categories matter especially for manufacturers (you'll see this exact breakdown in the Bausch Health example below):

A pure retailer (a store that buys finished products and resells them, adding no manufacturing) only ever has "finished goods", it never has raw materials or WIP, because it doesn't manufacture anything.

Why does this chapter matter so much?

Inventory is usually one of the largest current assets on a goods-based company's balance sheet, and cost of goods sold (COGS), the expense inventory eventually becomes, is usually the largest single expense on the income statement. A small percentage error or a subjective judgment call in how inventory is costed can move net income by a lot. That's exactly why this chapter exists: almost nothing about how much inventory you have physically is in dispute (you can count it), the real accounting problem is entirely about what dollar value to attach to those physical units, and when that dollar value moves from the balance sheet (as inventory) to the income statement (as COGS).

The one formula that runs through the entire chapter

Inventory cost flow equation: Beginning inventory + Purchases = Cost of goods sold + Ending inventory

Plain-English version: think of inventory like a bathtub. Water flowing in = purchases (or, for a manufacturer, production). What was already in the tub = beginning inventory. Some water drains out during the period = COGS (goods that left, i.e., were sold, or lost to theft/damage). Whatever's left in the tub at the end = ending inventory. The tub's "water in" always equals "water that drained out" plus "water still there", there's no way around this identity. Every topic in this chapter (cost flow assumptions, errors, writedowns) is really just a different angle on how we split the same total dollar amount between "drained out" (COGS, income statement) and "still in the tub" (ending inventory, balance sheet).

Rearranged, this is how you'll actually solve most problems:

Cost of goods sold = Beginning inventory + Purchases − Ending inventory

Asset vs. expense: the basic distinction this chapter keeps testing

When a company spends money, that cost either: 1. Becomes an asset (capitalized), sits on the balance sheet because it's expected to produce future economic benefit (a future sale), or 2. Becomes an expense (expensed), hits the income statement immediately because it doesn't meet that "future benefit" bar, or the benefit has already been used up.

Inventory costing is really just a specific, detailed application of this universal question: does this dollar belong in inventory (asset), or should it be expensed right now? You'll see this exact question asked repeatedly, for shipping costs, factory overhead, management salaries, and more.

Debits and credits refresher for inventory

If your journal-entry muscle memory is rusty, here's the pattern you'll see throughout this chapter:

Why COGS is debited, not inventory credited to "nothing": debiting an expense account and crediting the asset account is how you record "this asset's value left the balance sheet and became an expense", the fundamental accounting-equation trade-off (assets down, on the other side equity down via the expense).

Perpetual vs. periodic, in one sentence each (full detail in Part A)

• Perpetual system: the books are updated every time inventory moves, you always know both the quantity and cost of inventory and COGS, in real time.
• Periodic system: the books are updated only at period-end, after a physical count: COGS is a "plug" figure calculated backward from the cost flow equation, not tracked transaction-by-transaction.

Part A: Information Systems for Inventory Control

(LO 6-1)

1. Perpetual system

A perpetual inventory system directly tracks every addition to and withdrawal from inventory. At any point in time, the company can pull both inventory quantity on hand and COGS straight from the accounting records.

With cheaper technology and data management, perpetual systems are increasingly common because they give management timely information for inventory decisions. Important nuance: even with a perpetual system, companies still need to do a physical inventory count, the perpetual records might not match reality (theft, damage, data-entry errors).

2. Periodic system

A periodic inventory system does not continuously track inventory/COGS. At period-end, the company counts inventory, costs it, and then derives COGS backward using the cost flow equation (beginning inventory + purchases − ending inventory count = COGS).

3. Comparison and illustration: Vanderhoof Limited

Facts: beginning inventory $200,000; purchases $700,000; year-end count shows $300,000 in inventory. If Vanderhoof used a perpetual system, that system would separately indicate $500,000 of goods sold during the year (tracked in real time).

Exhibit 6-1: T-accounts for Vanderhoof's inventory under both systems ($000s)

*Determined from perpetual records (the "expected" COGS as goods are recorded sold in real time). †Determined at year-end after the inventory count, the "plug" figure that balances the account.

The key insight: under both systems, the balance sheet ends up showing $300,000 for inventory and the income statement shows $600,000 for COGS, the choice of system doesn't change the final reported numbers. What differs is that the perpetual system can further split that $600,000 into $500,000 of goods actually sold plus $100,000 of "shrinkage" (inventory losses from theft or breakage), information the periodic system simply cannot produce, because it never separately tracked expected vs. actual COGS.

Exhibit 6-2: Journal entries for Vanderhoof's transactions ($000s)

Why the periodic system uses a separate "Purchases" account: "Purchases" is a temporary account, closed out each year, it exists so the company can distinguish inventory changes coming from actual purchases versus adjustments from the physical count (or writedowns, see Part E).

Bottom line (per the text): a perpetual system gives management more, timelier information for inventory decisions; both systems produce different bookkeeping but the same final financial statement numbers. Whether you use periodic or perpetual also interacts with which cost flow assumption you use, that interaction is Part D below.

Part B: Initial Recognition and Measurement

(LO 6-2, pages 272–274, "Manufactured goods," are your core-assigned reading here; Part B.1 below is useful lead-in context.)

IAS 2 ¶10 states the general recognition criterion: "The cost of inventories shall comprise all costs of purchase, costs of conversion, and other costs incurred in bringing the inventories to their present location and condition." This is the same basic logic used for most other assets later in your course: include costs needed to obtain the item and get it to where/how it needs to be to generate revenue.

1. Purchased goods

For goods bought for resale: inventory cost = purchase price + any non-recoverable taxes + shipping/handling + any other costs incurred up to the point the product is ready for sale at its intended location. Costs incurred after that point (retail space, sales staff) cannot be capitalized into inventory, those are period costs.

Free on board (F.O.B.): the shipping term indicating the point at which the buyer takes legal possession of goods in transit. - F.O.B. origin (shipping point): buyer takes possession the moment goods leave the supplier's premises. - F.O.B. destination: buyer takes possession only once goods arrive at the buyer's premises.

Why this matters at year-end: a company must include in its own inventory (1) goods physically on its premises, plus (2) inbound goods in transit that are F.O.B. origin (already legally theirs), plus (3) outbound goods in transit that are F.O.B. destination (still legally theirs until the customer receives them). Miss this and you'll misstate year-end inventory.

Consignment (cross-reference to Chapter 4 revenue recognition): in a consignment arrangement, the consignee (who holds and sells the goods) is just an intermediary for the consignor (who owns the goods). Since risks/rewards of ownership never transfer to the consignee, consigned goods do not belong in the consignee's inventory, they still belong to the consignor.

2. Manufactured goods (pages 272–274, core assigned)

Manufacturing is more complex: raw materials get converted into finished goods using labour, machines, and other resources.

Product costs: all costs of acquiring raw materials and converting them to finished goods, materials, production labour (including factory supervision), variable overhead (e.g., electricity), and fixed overhead (e.g., heating). These get capitalized into inventory. Period costs: costs not closely tied to production, marketing, administration, accounting, finance. These are expensed in the period incurred, never capitalized into inventory.

The hard case is fixed overhead (e.g., factory rent or depreciation), materials, labour, and variable overhead are uncontroversially product costs, but fixed overhead has two competing treatments:

Exhibit 6-3: Product vs. period costs under variable vs. absorption costing

3. Manufactured goods with abnormal production levels (pages 272–274 continued)

Absorption costing creates a distortion risk when actual production deviates significantly from normal production levels.

a. Production above normal: Winfield Weavers. Variable cost $40/unit, sale price $100/unit, fixed overhead $3,000/year total.

Exhibit 6-4: Winfield Weavers at two production levels

What just happened: producing 100 extra, unsold units let Winfield spread its fixed $3,000 overhead over more units ($10/unit instead of $15/unit), lowering the total cost baked into each of the 200 units actually sold, which lowers COGS and raises reported gross margin, purely from a production-volume decision, not from any genuine improvement in cost efficiency or pricing power.

b. Production below normal. The opposite problem: unusually low production would inflate the per-unit fixed cost if you simply divided actual (low) fixed costs among actual (few) units, overstating inventory value. IAS 2 ¶13 resolves this: "The amount of fixed overhead allocated to each unit of production is not increased as a consequence of low production or idle plant. Unallocated overheads are recognized as an expense in the period in which they are incurred."

Extreme case for intuition: an idle plant (e.g., during a strike) produces zero units, there's no way to "absorb" fixed overhead into units that don't exist, so the only sensible treatment is to expense it directly.

Numeric illustration (Winfield Weavers again): normal production = 200 units, standard fixed overhead rate = $15/unit ($3,000 ÷ 200). If actual production is only 120 units: capitalized fixed overhead = 120 × $15 = $1,800; the remaining $3,000 − $1,800 = $1,200 must be expensed immediately as unallocated overhead (it is never spread across the 120 units at a higher rate).

Part C: Subsequent Measurement and Derecognition: Cost Allocation Between the Balance Sheet and Income Statement

(LO 6-3)

Once costs are capitalized into inventory, they must eventually be derecognized (i.e., removed from the balance sheet by being expensed). This section covers how much stays on the balance sheet vs. gets expensed for a given period. Everything here is governed by the cost flow equation you met in Part 0:

Exhibit 6-5: Inventory cost flow equation

Beginning inventory + Purchases = Cost of goods sold + Ending inventory (= "Cost of goods available for sale," abbreviated COGAS)

(Note: "purchases" here is used broadly to also mean goods manufactured, net of any purchase discounts/returns.)

Three methods exist to split COGAS between COGS and ending inventory: specific identification, cost flow assumptions, and the retail inventory method.

1. Specific identification

The most accurate but most costly method, track the actual individual cost of each specific unit. Usually reserved for high-value, individually distinguishable items (though falling technology costs are expanding its use).

Why it's risky for indistinguishable items: suppose a furniture store buys identical chairs, some at $100 and some at $105. If it wants to report higher income, it could simply choose to say the $100 chairs were the ones sold, leaving the $105 ones in ending inventory, pure earnings management, since the chairs are truly interchangeable. IAS 2 addresses this directly:

IAS 2 ¶23: "The cost of inventories of items that are not ordinarily interchangeable ... shall be assigned by using specific identification of their individual costs." IAS 2 ¶25: "The cost of inventories, other than those dealt with in paragraph 23, shall be assigned by using the first-in, first-out (FIFO) or weighted-average cost formula."

In short: specific identification is only appropriate for genuinely distinguishable items (e.g., serial-numbered goods), not as a discretionary choice for identical items.

2. Cost flow assumptions

For everything else, we have one bundle of costs (COGAS) that must be split systematically, this systematic choice is the cost flow assumption.

Exhibit 6-6 reconstructed: Schematic: allocating COGAS between COGS and ending inventory

  Beginning inventories  ─┐
                          ├──▶  Cost of goods available for sale (COGAS)  ──▶ Allocation ──┬──▶ COGS
  Purchases             ─┘                                                                 └──▶ Ending inventories

Three options:

1. FIFO, remove the oldest costs first
2. LIFO, remove the newest costs first
3. Weighted average, something in between

Important distinction: these are assumptions about the flow of costs, not the flow of physical goods. A grocer's actual milk rotation is (hopefully) FIFO in reality, but the accounting method chosen for cost allocation purposes can differ from the physical handling practice.

Exhibit 6-7: Westwold Water Company data (used for all three methods below)

(Assume Westwold uses the periodic method of inventory control for this illustration.)

a. First-in, first-out (FIFO)

Expenses the oldest costs first; the most recent costs remain on the balance sheet, hence FIFO is equivalently nicknamed "last-in-still-here" (LISH).

Exhibit 6-8 reconstructed: FIFO for Westwold

Beginning inv. (100 @ $1) ─┐
Purchase #1    (100 @ $1)  ├──▶ COGS = $400  (300 units: the three cheapest layers)
Purchase #2    (100 @ $2) ─┘

Purchase #3    (100 @ $3) ─┐
Purchase #4    (100 @ $4) ─┴──▶ Ending inventory = $700  (200 units: the two priciest, most recent layers)

FIFO allocates $400 to COGS and $700 to ending inventory, you can get there by starting with the oldest layers and working forward for COGS, or (equivalently) starting with the newest layers and working backward for ending inventory.

b. Last-in, first-out (LIFO)

Expenses the most recent costs first; the oldest costs remain in inventory.

Exhibit 6-9 reconstructed: LIFO for Westwold

Beginning inv. (100 @ $1) ─┐
Purchase #1    (100 @ $1) ─┴──▶ Ending inventory = $200  (200 units: the two oldest layers)

Purchase #2    (100 @ $2) ─┐
Purchase #3    (100 @ $3)  ├──▶ COGS = $900  (300 units: the three most recent layers)
Purchase #4    (100 @ $4) ─┘

LIFO allocates $900 to COGS and $200 to ending inventory. Since Westwold's costs were rising ($1→$4/unit), LIFO shows higher COGS and lower income than FIFO.

Currently, IFRS and ASPE both prohibit LIFO. It remains permitted (and used) in the United States for both financial and tax reporting; it was also allowed under old CICA Handbook rules until the end of 2007.

c. Weighted-average cost (WAC)

Exhibit 6-10 reconstructed: WAC formula

WAC per unit = (Beginning inventory + Purchases) ÷ Units available for sale = Cost of goods available for sale ÷ Units available for sale

Exhibit 6-11 reconstructed: WAC for Westwold

WAC per unit = $1,100 ÷ 500 units = $2.20/unit

WAC allocates $660 to COGS (300 units × $2.20) and $440 to ending inventory (200 units × $2.20); $660 + $440 = $1,100 = COGAS, as required.

Exhibit 6-12: Comparison of the three methods for Westwold

Pattern: FIFO → lowest COGS → highest income. LIFO → highest COGS → lowest income. WAC → in between. This pattern is a direct consequence of rising unit costs over the period, it would reverse if costs were falling.

d. Comparison of cost flow assumptions

To judge these methods, consider three things: balance sheet valuation quality, income statement matching quality, and resistance to earnings manipulation.

Exhibit 6-13: Comparison of cost flow assumptions

Important caveat: "LIFO dipping." LIFO's matching advantage assumes inventory levels aren't shrinking. If units sold exceed units purchased in a period, LIFO is forced to dip into old, outdated cost layers from prior years, undermining the matching benefit.

Canadian companies cannot use LIFO for tax reporting either; the US permits it for both financial and tax reporting (the textbook notes further discussion is in this chapter's Appendix, which is not part of your provided material).

3. Retail inventory method

The retail inventory method is popular for retailers with many low-value products (supermarkets, department stores), it's far easier to observe selling prices (marked on the shelf) than to track each item's cost. The method estimates cost by applying an average profit margin (discount) to the known retail price, then uses the cost flow equation to back into COGS.

Basic mechanic: if the average markup is 25%, an $80-cost product retails for $100 ($80 × 1.25); average margin = 20% ($20 profit ÷ $100 revenue), so the cost percentage = 80%. Apply that 80% to any specific product's retail price to estimate its cost, e.g., a $40 retail item is assigned an estimated cost of $32 ($40 × 80%).

Caveat: this only works well if the margin is fairly uniform. Enterprises with very different margins across product categories (clothing vs. kitchen appliances) need to tabulate categories separately, and discounted items must be segregated from regularly priced ones (since a discount changes the margin).

Retail pricing terminology. Suppose a product costs $100, with a normal selling price of $150 (50% standard markup). The retailer then adjusts the price sequentially to $160, $130, $80, and $110.

Retail Pricing Terminology diagram reconstructed

Retail
price
$160 ┤        ╭─Additional──╮      ╭──Mark-up───╮
     │        │  mark-up    │      │ cancellation│
$150 ┼────────╯             ╰──────╯             │  ←── Normal selling price (reference point)
     │  ╭─Mark-up─╮                              │
     │  │         │                        ╭─Mark-down─╮
$130 │  │         │                        ╰───────────┤
     │  │         │                                     │
$110 │  │         │                       ╭─Mark-down───╯
     │  │         │                       │ cancellation
$100 ┼──╯         │                       │
Cost │            │                       │
 $80 │            ╰───────────────────────╯
     └──────────────────────────────────────────────────▶ Time

The normal selling price ($150) is the key reference point, it separates: - upward moves into regular markup ($100→$150, i.e. +$50) vs. additional markup ($150→$160, +$10); - downward moves into markup cancellation (reversing an additional markup back toward $150) vs. markdown (falling below $150).

In this specific example: markup = $50 (cost→normal price); additional markup = $10 ($150→$160); the drop from $160 to $130 (−$30) splits into a $10 markup cancellation (undoing the additional markup back to $150) plus a $20 markdown (going below the $150 reference point); then a further markdown of $50 ($130→$80); then a markdown cancellation of $30 (the recovery from $80 to $110, still below the $150 reference point, so it's a "cancellation" of markdown, not a new markup).

For accounting purposes, none of this markup/markdown terminology matters directly, what matters is simply the estimated gross margin on the reporting date, regardless of which combination of ups and downs produced it.

Worked example: Keats Kotton (specialty clothing retailer; two lines, standard and deluxe; standard products marked up 100%, deluxe marked up 150%; in the last week before year-end, 10 standard products were discounted 40% off).

Exhibit 6-14: Keats Kotton inventory information

Exhibit 6-15: Margins by product line

*A product costing $1 is marked up 100% to $2, then discounted 40% down to $1.20. Cost as % of retail = $1 ÷ price × 100%.

Exhibit 6-16: Estimating Keats Kotton's ending inventory (retail method)

Exhibit 6-17: Keats Kotton's COGS via the cost flow equation

Related but distinct: the gross margin method. This reverses the retail method's order of operations: (1) estimate COGS directly by applying an average gross margin to sales, (2) back into ending inventory using the cost flow equation. It's used for interim reporting when a physical count isn't cost-effective, but because it relies entirely on an estimated margin (no direct information on actual COGS or inventory), it is not normally accepted for annual financial statements, unlike the retail inventory method, which is accepted per IAS 2 ¶21–22.

Part D: Interaction of Cost Flow Assumptions and Inventory Control Systems (bonus/bridging content)

(LO 6-3, continued)

The key question: does the periodic-vs-perpetual choice (Part A) change the dollar results you get from a given cost flow assumption (Part C)? Answer: it depends on the method. It does not matter for FIFO. It does matter for weighted-average, enough that the perpetual version of weighted-average gets its own name, the moving-average method.

Illustration: Vallican Polypropylene. Beginning inventory: 30,000 tonnes @ $1,000/tonne = $30,000,000. Production: January 10,000 tonnes @ $1,100 ($11,000,000); February 8,000 tonnes @ $1,250 ($10,000,000); March 11,000 tonnes @ $1,300 ($14,300,000), total 29,000 tonnes, $35,300,000. Shipments: Feb 20 → 12,000 tonnes; Mar 11 → 20,000 tonnes (32,000 tonnes total).

Exhibit 6-18: Weighted-average: periodic vs. perpetual (moving-average)

Periodic weighted-average (computed once, at quarter-end):

Perpetual moving-average (recomputed after every purchase):

The two methods genuinely disagree: periodic gives COGS of $35.4M and ending inventory of $29.9M; perpetual (moving-average) gives a lower COGS of $33.8M and higher ending inventory of $31.5M. This particular direction isn't a general rule, it flips depending on whether costs are rising or falling and exactly when shipments occur relative to production.

Exhibit 6-19: FIFO: periodic vs. perpetual (same result both ways)

Periodic FIFO: COGAS $65,300,000 (59,000 tonnes) → ship out first 30,000 tonnes from beginning inventory (@ $1,000 = $30,000,000) plus 2,000 tonnes from January production (@ $1,100 = $2,200,000) → ending inventory 27,000 tonnes = $33,100,000.

Perpetual FIFO: tracking each shipment against whatever's oldest at that moment: Feb 20 ships 12,000 tonnes from beginning inventory (@$1,000); Mar 11 ships the remaining 18,000 tonnes of beginning inventory (@$1,000) plus 2,000 tonnes from January production (@$1,100), ending inventory 27,000 tonnes = $33,100,000. Identical to the periodic result.

Why FIFO doesn't care, but WAC does: FIFO always removes the same ordered layers of cost regardless of when you check, the oldest-to-newest sequence doesn't change based on your bookkeeping frequency. Weighted-average, by contrast, is recalculated every time you check under a perpetual system, so shipments occurring at different points get costed at different average rates, producing a genuinely different total than computing one single average at period-end.

Part E: Subsequent Measurement: Avoiding Overvaluation of Inventories

(LO 6-4, pages 284–285, core assigned)

Representational faithfulness requires that assets not be overvalued. Accounting standards therefore require inventory to be reported at the lower of cost and market (LOCM): if market price falls below cost, write down to that lower value and record a loss; if market price exceeds cost, no upward adjustment is made (inventory is never written up above cost).

Journal entry for a $100 writedown:

Dr. Loss from decline in inventory value (COGS)     100
    Cr. Inventory                                          100

In practice, companies fold this loss into COGS on the income statement rather than showing it as a separate line.

1. Meaning of "market"

Two competing interpretations of "market" exist conceptually:

IFRS and ASPE currently emphasize net realizable value (the output view). An important nuance for manufacturers: raw materials are only evaluated for writedown if the finished product they'll become also requires a writedown. If the end product is still expected to sell above its total cost, the raw material inputs are not written down, even if input costs (e.g., commodity prices) have fallen. When a writedown is needed, replacement cost is often used for raw materials/WIP specifically, since it's more readily/reliably observable than trying to estimate NRV all the way through to the finished product.

Worked example: Yahk Petroleum (refinery: buys crude, produces gasoline). Crude oil cost: $150/barrel. Processing cost to convert to gasoline: $100/barrel. At year-end, crude price falls to $50/barrel; gasoline price falls to $200/barrel.

• Finished goods (gasoline): cost = $150 + $100 = $250/barrel; NRV = $200/barrel → gasoline needs a $50/barrel writedown.
• Raw materials (crude): because the finished product did require a writedown, crude must also be assessed. Carrying value $150/barrel vs. replacement cost $50/barrel → crude needs a $100/barrel writedown.

Reversals are rare in practice. If market value later recovers, a company can reverse some/all of a prior writedown, but only for the same physical inventory still on hand at both dates, and most companies turn over inventory faster than that window allows.

2. Unit of evaluation

How granular should the LOCM comparison be, can gains on one product offset losses on another? IAS 2 ¶29: "Inventories are usually written down to net realizable value item by item. In some circumstances, however, it may be appropriate to group similar or related items. This may be the case with items of inventory relating to the same product line that have similar purposes or end uses, are produced and marketed in the same geographic area, and cannot be practicably evaluated separately from other items in that product line. It is not appropriate to write inventories down on the basis of a classification of inventory, for example, finished goods, or all the inventories in a particular operating segment."

Practical translation: evaluate at the most detailed level practical, a bicycle manufacturer with five distinct products evaluates each product separately (you can't let a strong Product A offset a weak Product B), but the individual raw-material parts that go into assembling one bicycle can reasonably be evaluated together as a single unit.

3. Environmental and social factors (ESG)

Tightening environmental standards can suddenly devalue whole categories of inventory, e.g., jurisdictions banning gas-powered vehicles by a target year (2035 is cited), or bans on single-use plastics. Similarly, forced/child labour findings in a supply chain can destroy a product's value overnight (reputational boycotts). Canada's Fighting Against Forced Labour and Child Labour in Supply Chains Act (passed May 2023, in effect January 1, 2024) requires companies to report proactive steps to prevent/reduce forced or child labour risk in their supply chains and to remediate it when discovered; the Canada Border Services Agency can seize goods produced in violation. Practical accounting link: goods sourced in violation of these standards face real cost and likely reduced NRV, this is a genuine, quantifiable inventory-valuation risk, not just a compliance/PR issue.

Focus on Data Analytics

Scenario: a finance professional at a company like Samsung Electronics faces an overwhelming number of SKUs (raw materials, components, finished products) to evaluate for LOCM, doing this manually could require entire dedicated teams.

The solution the text highlights: automated web scraping. Scraping tools can pull current market prices for raw materials, components, and finished goods (e.g., scraping a marketplace like Amazon to check finished-goods market prices) and feed them directly into a spreadsheet or database, refreshed on demand. You don't need to be a professional programmer, beginner-friendly Python is one route, or off-the-shelf tools like Octoparse offer ready-made scraping templates. Why this matters for you as an analytics-stream student: LOCM is conceptually simple but operationally enormous at scale, this is a concrete example of how data tooling turns a theoretically-correct-but-impractical manual process into something a real finance team can actually execute company-wide.

Part F: Accounting for Inventory Errors

(LO 6-5, pages 287–288, core assigned)

Why inventory errors are tricky: in a periodic system, the inventory account is used twice in the COGS calculation (as both the beginning balance and the ending balance, see the cost flow equation). This means one error typically distorts two different fiscal years, and inventory misstatements often travel with related errors in purchases/accounts payable.

All four examples below involve Zeballos Inc., are independent of each other, and each involves a $5,000 item near the December 31, 20X1 year-end.

Inventory Error Example 1: Inventory included, purchases omitted

Zeballos forgets to record a $5,000 purchase invoice, but the related inventory was correctly counted and included.

• Ending inventory: correctly stated. Beginning inventory: assumed correct.
• Rearranging the cost flow equation (COGS = Beg. inv. + Purchases − End. inv.): omitting $5,000 of purchases directly understates COGS by $5,000.
• Follow-through: the vendor will eventually chase Zeballos for payment, so the $5,000 will likely get recorded in 20X2 instead, overstating purchases (and COGS) in 20X2 by the same $5,000.

Inventory Error Example 2: Inventory omitted, purchases included

Goods shipped F.O.B. shipping point (so legally Zeballos's the moment they left the supplier) were still in transit on Dec. 31, 20X1 and got left out of the physical count, but the invoice was correctly recorded in purchases/accounts payable.

• Direct effect: ending inventory understated by $5,000.
• Indirect effect (via the cost flow equation): understating ending inventory by $5,000 overstates COGS by $5,000 (fewer dollars staying on the balance sheet means more must have "gone" to COGS, per the equation).

Inventory Error Example 3: Inventory omitted, purchases omitted

Same $5,000 of inbound goods omitted from the count and the invoice not recorded until the following year (both errors together).

• Both the asset (inventory) and liability (accounts payable) are understated by $5,000.
• Net COGS effect is zero: the understated ending inventory overstates COGS by $5,000, while the understated purchases understates COGS by $5,000, the two effects cancel exactly. This also makes sense via the balance sheet equation: assets and liabilities are both understated by the same amount, so retained earnings (and therefore income) is unaffected.

Inventory Error Example 4: Incorrect costing

Zeballos fails to capitalize $5,000 of shipping costs on 20X1 purchases, instead expensing it to "miscellaneous expenses." By year-end, 80% of the affected goods have already been sold (only 20% remain in ending inventory).

• Directly: miscellaneous expense is overstated by $5,000; purchases (i.e., inventory cost) is understated by $5,000.
• Since only 20% of the goods remain unsold, ending inventory is understated by only 20% × $5,000 = $1,000 (the rest already flowed to COGS regardless of the misclassification).
• Net COGS effect: understated purchases (−$5,000 to COGS via the equation) combined with understated ending inventory (+$1,000 to COGS via the equation, since less ending inventory means more went to COGS) nets to a $4,000 understatement of COGS.
• Combined with the $5,000 overstated misc. expense: net income effect = +$4,000 (from understated COGS helping income) − $5,000 (from the overstated separate expense hurting income) = net understatement of $1,000 in 20X1 net income.

Exhibit 6-20: Summary of all four errors across both years ("−" = understated, "+" = overstated, "0" = correct)

20X1:

20X2 (the follow-through year):

The big picture: by the end of the second year, every balance sheet figure has self-corrected back to $0 (correct), because the ending inventory in 20X1 becomes the beginning inventory in 20X2, forcing the error to "wash out." What doesn't wash out cleanly is the allocation of income between the two years: 20X1 and 20X2 net income are individually wrong (in opposite directions), even though the two-year cumulative net income effect is zero. This is exactly why inventory errors are dangerous: they can make a single year look artificially better or worse, even though "the books balance eventually."

Part G: Presentation and Disclosure

Per Chapter 3's rules, inventories must appear as their own separate line item on the balance sheet. Cost of sales, however, has no equivalent explicit presentation requirement on the income statement: IAS 1 only implies "operating expenses" (which includes cost of sales) must be disclosed somewhere, not necessarily as its own face-of-statement line (most companies do show it anyway).

Required disclosures when material writedowns occur: the amount of writedowns, any reversals in the period, and the amount of inventory that's been written down. If inventory has been pledged as collateral for a loan/liability, that must be disclosed too.

Real example: Bausch Health's actual accounting policy note (per your source): "Inventories comprise raw materials, work in process, and finished goods, which are valued at the lower of cost or net realizable value, on a first-in, first-out basis. The cost value for work in process and finished goods inventories includes materials, direct labor, and an allocation of overheads." And: "The Company evaluates the carrying value of inventories on a regular basis, taking into account such factors as historical and anticipated future sales compared with quantities on hand, the price the Company expects to obtain for products in their respective markets compared with historical cost and the remaining shelf life of goods on hand."

Part H: A Practical Illustration: Canadian Tire Corporation, Limited

Canadian Tire's 2022 financial statements reported $3,216 million in merchandise inventories. Per Note 3 (page 94 of their statements), all inventories are finished goods, measured at the lower of cost and net realizable value, where NRV = estimated selling price in the normal course of business, less estimated selling expenses. Canadian Tire uses the weighted-average cost method, with cost including "costs incurred in bringing the merchandise inventories to their present location and condition."

An interesting real-world wrinkle, vendor subsidies. Suppliers sometimes pay Canadian Tire subsidies, which function as negative costs. Per the company's own policy: "Cash consideration received from vendors is recognized as a reduction to the cost of related inventory, unless the cash consideration received is either a reimbursement of incremental costs incurred by the Company or a payment for assets or services delivered to the vendor." In other words, judgment is required to decide whether a given vendor payment should reduce inventory cost or instead offset a specific expense, not a mechanical, formulaic decision.

Part I: Potential Earnings Management Using Inventories

1. Overproduction

As established in Part B: producing above the normal level lowers the fixed-overhead cost absorbed per unit, which lowers COGS on the units actually sold and inflates net income, a purely production-volume-driven effect, not a genuine improvement. Red flag for users/auditors: an unusual buildup of inventory at year-end can signal excess production undertaken specifically to manage earnings.

2. Including non-production costs in inventory

Any cost is either expensed or capitalized. Wrongly capitalizing a cost that should have been expensed (e.g., including non-production management salaries in inventory cost) inflates the inventory asset and reduces the (wrong) expense category, temporarily keeping that cost off the income statement until the inventory is eventually sold. Red flag: a falling gross margin percentage can be a symptom, since stuffing too much cost into inventory eventually inflates COGS when that inventory is sold.

3. Not identifying impaired or discounted items

Simply failing to record a required LOCM writedown (on obsolete, damaged, or demo-unit inventory) inflates income by the amount that should have been written off. For retailers specifically using the retail inventory method: if management reverses markdowns just before year-end, discounted items get miscounted as regular-priced merchandise, and the retail method then overstates their imputed cost/value. Red flag for auditors (not visible to ordinary readers): verify that recent actual sale prices genuinely support the values assigned to inventory on hand.

Part J: Substantive Differences: IFRS vs. ASPE

Why this matters: it's a narrower difference than some other IFRS/ASPE gaps you've seen (e.g., Chapter 3's OCI difference is much bigger), but it's a good reminder that ASPE often gives private enterprises more discretion rather than a wholly different concept.

Additional Practice (supplementary, not from your textbook)

These two problems are my own construction, built specifically because you asked for more practice and exposure. They are clearly not quotes or exhibits from your source material: I'm flagging that explicitly so you never mistake them for textbook content if you're cross-referencing for an assignment.

Practice Problem 1: FIFO / LIFO / WAC drill

Bowmanville Bicycles has the following activity in its periodic inventory system for the month:

Try it yourself first, then check below:

• FIFO: COGS uses the 3 oldest layers needed to reach 100 units → 50 @ $60 + 50 @ $65 = $3,000 + $3,250 = $6,250 COGS; ending inventory = the 50 newest units = 50 @ $70 = $3,500. (Check: $6,250 + $3,500 = $9,750 ✓.)
• LIFO: COGS uses the newest layers first → 50 @ $70 + 50 @ $65 = $3,500 + $3,250 = $6,750 COGS; ending inventory = the 50 oldest units = 50 @ $60 = $3,000. (Check: $6,750 + $3,000 = $9,750 ✓.)
• WAC: WAC/unit = $9,750 ÷ 150 = $65/unit; COGS = 100 × $65 = $6,500; ending inventory = 50 × $65 = $3,250. (Check: $6,500 + $3,250 = $9,750 ✓.)
• Pattern check: costs were rising ($60→$70), so FIFO gives the lowest COGS/highest income, LIFO the highest COGS/lowest income, WAC in between, exactly the same pattern as Westwold Water Company above. If you got a different ranking, re-check which layers you assigned to COGS vs. ending inventory.

Practice Problem 2: Inventory error, self-check

Nakusp Novelties forgot to include $2,000 of goods in its Dec. 31, 20X1 physical count (an inventory clerk missed a back-storeroom shelf). The related purchase was correctly recorded in accounts payable/purchases.

Question: what's the effect on 20X1 ending inventory, 20X1 COGS, and 20X1 net income?

Work it through using the cost flow equation (COGS = Beg. inv. + Purchases − End. inv.) before checking below.

Answer: this is structurally identical to Inventory Error Example 2 above (inventory omitted, purchases correctly included). Ending inventory is understated by $2,000. Since ending inventory is subtracted in the cost flow equation, understating it overstates COGS by $2,000. An overstated COGS understates net income by $2,000 in 20X1. (And, following the same logic as Example 2's follow-through: in 20X2, beginning inventory carries the $2,000 understatement forward, which will reverse the effect on 20X2's COGS and net income, net income will be overstated by $2,000 in 20X2, exactly cancelling the 20X1 understatement over the two years combined.)

Executive Summary (One Page)

This chapter tackles three questions that apply to any asset, specifically as they play out for inventories: what costs get capitalized on initial recognition (Part B), how those capitalized costs get split between the balance sheet and the income statement over time (Parts C and D), and how inventory remaining on the balance sheet should be revalued downward if its value has fallen (Part E), plus a fifth issue unique to how thoroughly inventory and cost of goods sold are mechanically linked: what happens when errors creep into the system (Part F). Before any of that, Part A establishes that companies track inventory information either continuously (perpetual systems, which additionally reveal shrinkage) or only at period-end via a physical count (periodic systems, which cannot separate shrinkage from genuine sales), a distinction that doesn't change final reported numbers but does change how much operational insight management gets. On initial recognition, the central rule is that all costs needed to bring inventory to its saleable location and condition get capitalized, with manufactured goods requiring a further judgment call on fixed overhead: financial reporting mandates absorption costing (fixed overhead is a product cost) even though internal decision-making often prefers variable costing (fixed overhead as a period cost), a choice that opens the door to a specific, well-documented form of earnings manipulation via abnormal production volume.

The heart of the chapter is cost allocation: once costs are pooled as "cost of goods available for sale," they must be split between COGS and ending inventory using specific identification (for genuinely distinguishable items), a cost flow assumption (FIFO, LIFO, or weighted-average, for everything else), or the retail inventory method (a retailer-specific shortcut using markup percentages, not required per your syllabus but included for exposure).

FIFO and weighted-average are the only options permitted under IFRS/ASPE: ==LIFO is banned in Canada== (though still used in the US) precisely because it is the easiest of the three to manipulate through deliberate year-end purchasing decisions, despite arguably offering the best income-statement matching when inventory levels are stable. Whether a company uses a periodic or perpetual system interacts with this choice: FIFO produces identical results either way, while weighted-average genuinely differs (its perpetual version even gets its own name, moving-average), because recalculating the average with every purchase versus once per period changes which costs get averaged into which shipments.

Once inventory sits on the balance sheet, it must be tested against the lower of cost and (net realizable value, per current IFRS/ASPE practice), a rule that can cascade from finished goods back to raw materials, and one increasingly influenced by ESG-driven obsolescence risk such as environmental regulation or supply-chain labour violations. Finally, because the beginning and ending inventory balances both feed into the same COGS calculation, a single inventory error typically distorts two consecutive years' net income in offsetting directions even though the balance sheet fully self-corrects by the end of the second year, making inventory one of the clearest illustrations in the whole course of how thoroughly the balance sheet and income statement articulate with each other.

Key Takeaways

1. Everything in this chapter reduces to one equation: Beginning inventory + Purchases = COGS + Ending inventory. When in doubt, write this down and solve for the unknown.
2. Perpetual systems track inventory/COGS continuously (and can isolate shrinkage); periodic systems only compute COGS as a backward-solved "plug" at period-end after a physical count, but both report identical final financial-statement numbers.
3. Absorption costing (fixed overhead capitalized into inventory) is mandatory for external IFRS/ASPE reporting, even though variable costing (fixed overhead expensed immediately) is often preferred internally.
4. Producing above normal volume mechanically lowers per-unit fixed overhead and inflates gross margin, a red flag for earnings management, not necessarily a sign of genuine efficiency gains.
5. Below-normal production never triggers a higher per-unit fixed overhead rate, unallocated fixed overhead is expensed immediately instead, preventing artificially inflated inventory values.
6. FIFO and weighted-average are the only cost flow assumptions IFRS/ASPE permit; LIFO is banned in Canada specifically because it's the easiest to manipulate through year-end purchasing decisions ("LIFO dipping").
7. FIFO gives the highest-quality balance sheet valuation (current costs remain in inventory); LIFO (where permitted) gives the best income-statement matching, but never both at once from a single method.
8. The periodic/perpetual choice doesn't affect FIFO results, but it does affect weighted-average, the perpetual version is specifically called the moving-average method.
9. Lower of cost and market (LOCM) never allows inventory to be written up above cost, only down, and IFRS/ASPE use net realizable value (not replacement cost) as the primary "market" benchmark for finished goods.
10. Raw materials/WIP are only written down if the finished product they'll become is also impaired, not simply because input costs fell.
11. A single inventory error distorts two consecutive fiscal years (in opposite directions) even though the balance sheet fully self-corrects after the second year, always trace both the direct and indirect (cost flow equation) effects.
12. Inventory-related earnings management can happen through real operating decisions (overproduction) as well as through accounting judgment calls (miscapitalizing costs, skipping required writedowns), auditors and analysts should watch gross margin trends and year-end inventory buildups as warning signs.

Common Misconceptions and Mistakes

• Confusing the flow of physical goods with the cost flow assumption. A grocer can physically rotate stock FIFO (oldest milk sold first) while still using a different cost flow assumption for accounting purposes, these are independent choices.
• Assuming perpetual vs. periodic changes the final financial statement numbers. It doesn't, both produce the same ending inventory and COGS; the difference is purely in the information available along the way (e.g., visibility into shrinkage).
• Treating "market" in LOCM as replacement cost by default. Under current IFRS/ASPE, "market" primarily means net realizable value, not replacement cost, replacement cost is only the fallback used specifically for raw materials/WIP once a writedown is already triggered.
• Writing inventory back up when prices recover, without checking that it's genuinely the same physical goods still on hand. Reversals are permitted but rare in practice, and only apply to the identical inventory that was written down and hasn't since been sold.
• Assuming higher production automatically means better performance. Under absorption costing, simply producing more (even unsold) units mechanically lowers reported COGS and raises gross margin, a volume effect, not necessarily genuine operating improvement.
• Believing an inventory error only affects one year. Because inventory feeds the COGS equation as both a beginning and ending balance, one error typically flows through two years' income statements, in opposite directions, even though the balance sheet is fully correct again by the end of year two.
• Assuming LIFO is simply "banned everywhere." It's banned under IFRS and ASPE (so, in Canada), but still permitted (and commonly used) in the United States for both financial and tax reporting, an important cross-border difference if you're ever comparing a Canadian company to a US peer.
• Forgetting F.O.B. terms at year-end. Goods in transit belong in your inventory if they're F.O.B. origin (inbound) or F.O.B. destination (outbound, still in transit to the customer), missing this is a classic cutoff error, directly related to Chapter 3's subsequent-events/cut-off material.
• Assuming the retail inventory method and the gross margin method are interchangeable. They reverse each other's logic (retail method estimates ending inventory first, then derives COGS; gross margin method estimates COGS first, then derives ending inventory) and only the retail method is accepted for annual financial statements.

Cheat Sheet

The core formula

Beginning inventory + Purchases = Cost of goods sold + Ending inventory (rearranged: COGS = Beginning inventory + Purchases − Ending inventory)

Cost flow assumptions at a glance

WAC formula

WAC per unit = Cost of goods available for sale ÷ Units available for sale

LOCM (lower of cost and market)

If Net Realizable Value < Cost  →  write DOWN to NRV, record a loss (never write UP above cost)
If NRV ≥ Cost                   →  no adjustment
Raw materials/WIP written down  →  ONLY if the finished product they become is also impaired

Product cost vs. period cost

Fixed overhead allocation rule

• Above-normal production → per-unit fixed overhead rate goes down (spread over more units), always allocate based on actual units when production exceeds normal.
• Below-normal production → per-unit fixed overhead rate is capped at the normal-volume standard rate; unallocated overhead is expensed immediately, never used to inflate the per-unit rate.

Inventory error quick-reference (effect on COGS via the cost flow equation)

Golden rule for any inventory error: plug your two numbers into COGS = Beg. inv. + Purchases − End. inv., see which side is wrong and by how much, and remember the error typically reverses direction in the following year as the wrong ending balance becomes the wrong beginning balance.

Key terminology glossary

End of study guide.

Cross-Chapter Connections

• Chapter 3: Accounting changes. Inventory errors are the cleanest worked application of Chapter 3's error-correction mechanics, and the two-year self-correction is why prior-year fixes land in Retained Earnings.
• Chapter 4: Consignment. Chapter 4 defers revenue until the right of return lapses; Chapter 6 keeps the goods in the consignor's inventory for the same reason. Two views of one control question.
• Chapter 1: Earnings management. Overproduction and skipped writedowns are Chapter 1's upward-bias motivations expressed through inventory.
• Chapter 2: Measurement. Lower of cost and net realizable value is a direct application of the measurement-basis and prudence discussion.
• Chapter 10: Impairment. LOCM and impairment share one logic: assets may not be carried above recoverable value. Chapter 10 applies it to non-current assets; Chapter 6 to inventory.

Common CPA Exam Traps

Key IFRS/ASPE Rules

Journal Entry / Calculation Walkthrough

Memory Anchors

Adversarial CPA Mini-Scenario

🎯 Key Takeaways for CPA Candidates

1. The cost flow equation BI + P = COGS + EI is the engine of the entire chapter. Every topic splits the same pool of dollars.
2. LOCM cascades finished goods → raw materials, never the reverse. If the finished product is unimpaired, raw materials are untouched regardless of input prices.
3. "Market" under IFRS/ASPE means net realizable value. Replacement cost is the fallback for raw materials/WIP only, and only once a writedown is triggered.
4. Inventory may be written down, never up above cost. Reversals apply only to the same physical goods still on hand at both dates.
5. Below-normal production caps the fixed overhead rate at the normal-capacity rate (IAS 2 ¶13); unallocated overhead is expensed immediately.
6. LIFO is prohibited in Canada under both IFRS and ASPE (IAS 2 ¶25), precisely because it is the easiest of the three to manipulate through year-end purchasing decisions.
7. FIFO gives identical results under periodic and perpetual. Weighted average does not, the perpetual version is moving average.
8. Specific identification is required for items not ordinarily interchangeable (IAS 2 ¶23), not merely permitted.
9. Writedowns are assessed item by item (IAS 2 ¶29); grouping is permitted only for similar items in the same product line, never by classification or segment.
10. One inventory error distorts two consecutive years' income in opposite directions while the balance sheet self-corrects. Both years must be addressed.
11. Consignment goods stay in the consignor's inventory, ownership follows control, not physical location. Same logic as Chapter 4.
12. Inventory earnings management operates through real operating decisions (overproduction) as well as accounting judgment (skipped writedowns, miscapitalized costs). Watch gross margin trends and year-end inventory buildups.

Retrieval Practice

Questions visible, answers hidden. Attempt each before expanding.

Source Fidelity & Obsidian QA