Inventory Systems



Module 4:
Inventory & Costing

Duration:
45-60 minutes

Level:
Beginner to Diploma-Level


Lesson Objectives

Define inventory and inventory systems

Distinguish between periodic and perpetual inventory systems

Record inventory transactions under each system

Identify businesses that use each inventory system

Understand how inventory systems affect Cost of Goods Sold

Explain the impact of inventory systems on financial statements


Key Vocabulary

Inventory
Inventory System
Periodic Inventory System
Perpetual Inventory System
Cost of Goods Sold
Physical Count
Purchases
Shrinkage


What Is an Inventory System?

An inventory system determines how and when inventory quantities and costs are recorded.

Inventory systems help businesses

Track goods available for sale
Calculate COGS accurately
Control theft and losses
Prepare reliable financial statements


Types of Inventory Systems

1. Periodic Inventory System

Inventory updated only at period-end
COGS calculated using a formula
Physical count required
Used by small businesses

COGS Formula | Periodic

Beginning Inventory
+ Purchases
− Ending Inventory
= COGS


Types of Inventory Systems

2. Perpetual Inventory System

Inventory updated after every transaction
COGS recorded at time of sale
Continuous tracking
Used by supermarkets, large retailers


Comparison | Periodic vs Perpetual

Feature
Inventory updates
COGS
Physical count
Accuracy

Periodic
End of period
Calculated
Required
Lower

Perpetual
Continuous
Recorded immediately
Used to verify
Higher



Journal Entries Comparison

Sale of Goods | Cash Sale
Periodic System

Cash
Sales Revenue

Dr
Cr


COGS recorded later


Journal Entries Comparison

Perpetual System

Cash
Sales Revenue
Cost of Goods Sold
Inventory

Dr
Cr
Dr
Cr



Identify the Inventory System

State whether Periodic or Perpetual

Inventory updated at year-end only

Used by supermarkets

COGS calculated using a formula

Inventory reduced at time of sale

Requires continuous record keeping


Fill in the Blanks

1. Under a ______ inventory system, inventory is updated continuously.

2. Under a ______ inventory system, COGS is calculated at period-end.

3. Shrinkage is discovered through a ______ count.


COGS Calculation | Periodic

A business has

Choose the most appropriate action
Beginning Inventory = 4,000
Purchases = 12,000
Ending Inventory = 3,500

Task
Calculate Cost of Goods Sold.


Journal Entry Practice

A business sells goods costing 2,000 for 3,200 cash.

Prepare journal entries under

Periodic system
Perpetual system


Mini Case Study

A clothing store wants to improve inventory control. Currently, it only updates inventory at the end of the year and experiences frequent stock losses.

Questions

Which inventory system is the store using?

What problems does this system cause?

Which inventory system should the store adopt? Why?

How would this change affect COGS recording?

How would it improve financial reporting?


Quick Quiz

What is an inventory system?

Name the two main types of inventory systems.

True or False | COGS is recorded only at period-end under the perpetual system.

Which system provides more accurate inventory records?

What formula is used to calculate COGS under the periodic system?

Answers ➧ Here

FIFO ➧ Here