Inventory in MESOS can be used in two ways:
- Operational Quantity Tracking — track how many units you have.
- Inventory Tracking — track both the quantity and accounting value of the stock.
Choose the method that matches how you manage your products.
1. Product, Parts or Service #
Product / Parts #
Use Product or Parts for physical items.
Physical items can:
- Have a stock quantity
- Be assigned to a Warehouse
- Use Inventory Tracking
- Be purchased and sold
- Have stock movements
Service #
Use Service for non-physical items such as:
- Consultancy
- Labour
- Professional services
- Maintenance services
Services do not use:
- Inventory Tracking
- Warehouse stock
- Inventory Opening Balance
2. Quantity #
Quantity is the current physical or operational quantity of a Product or Parts item.
Example:
You create:
Product: USB Cable
Quantity: 100
MESOS records that you currently have 100 units.
A Quantity can exist whether Inventory Tracking is enabled or disabled.
Having a Quantity does not automatically mean the stock is recorded as an accounting Inventory Asset.
3. Inventory Tracking Off #
Use Inventory Tracking = No when you only need to track the physical quantity of the product.
Example:
Quantity: 100
Inventory Tracking: No
MESOS keeps the 100 units as operational stock.
It does not create:
- An accounting Inventory Opening Balance
- Inventory Asset value
- Weighted Average Cost valuation
You can update operational quantities through the supported product and stock functions.
This option is suitable when you need basic stock quantity management but do not require inventory valuation in accounting.
4. Inventory Tracking On #
Use Inventory Tracking = Yes when MESOS should manage both:
- Stock quantity
- Stock accounting value
Inventory Tracking is normally used when the product should appear as an Inventory Asset in your accounts.
When Inventory Tracking is enabled, MESOS maintains inventory cost using Weighted Average Cost (WAC).
5. Starting Inventory #
If you create a new Inventory Tracked Product with existing stock, you must provide the opening inventory information.
Example:
Quantity: 100
Inventory Tracking: Yes
Inventory Opening Total Value: RM1,000
MESOS establishes:
100 units of stock
with a total inventory value of
RM1,000
The starting weighted average cost is therefore:
RM10 per unit
You will also need:
- Inventory Opening Total Value
- Inventory Opening Date
- Inventory Opening Reference
- Inventory Asset Account
- Warehouse
Important #
Purchase Price is not used automatically as your Inventory Opening Balance value.
The opening inventory value must be entered separately.
6. Starting With Zero Stock #
You may enable Inventory Tracking even when the product currently has no stock.
Example:
Quantity: 0
Inventory Tracking: Yes
No Inventory Opening Balance is created because there is no starting inventory.
Future stock can then be added through normal inventory transactions such as Purchases.
7. Existing Product With Stock #
An existing product may already have operational quantity before Inventory Tracking is enabled.
Example:
Current Quantity: 30
Inventory Tracking: No
If you later enable Inventory Tracking, MESOS uses the existing 30 units as the quantity to be valued.
It does not add another 30 units.
You will be required to enter the total value of the existing inventory.
Example:
Current Quantity: 30
Inventory Opening Total Value: RM300
MESOS starts Inventory Tracking with:
30 units
RM300 inventory value
RM10 weighted average cost
Inventory Tracking for an existing Product or Parts item must be started from Product Edit.
It cannot be activated through Bulk Update.
8. Adding Stock #
Once Inventory Tracking is enabled, do not directly edit the Quantity field to add stock.
Stock should be added through the appropriate inventory transaction.
Examples include:
- Purchase
- Inventory Opening
- Stock Adjustment
- Purchase Debit Note where applicable
- Other supported stock receipt movements
This allows MESOS to maintain both the quantity and value of the inventory correctly.
9. Selling Stock #
When an Inventory Tracked product is sold, MESOS:
- Reduces the stock quantity.
- Reduces the Inventory Asset value.
- Recognises the inventory cost as Cost of Goods Sold (COGS).
Example:
Current inventory:
100 units
Weighted Average Cost: RM10
You sell:
5 units
MESOS recognises inventory cost of:
5 × RM10 = RM50
Accounting effect:
Dr Cost of Goods Sold RM50
Cr Inventory Asset RM50
The sales revenue is recorded separately from the inventory cost.
10. Purchases #
For an Inventory Tracked product, a Purchase increases the quantity and inventory value.
Example:
Current stock:
100 units @ RM10 = RM1,000
Purchase:
100 units @ RM20 = RM2,000
New total:
200 units
RM3,000 inventory value
New Weighted Average Cost:
RM15 per unit
Future sales will use the applicable inventory cost maintained by MESOS.
11. Changing Quantity #
Inventory Tracking Off #
Quantity is operational stock.
Quantity changes do not create Inventory Asset accounting value.
Inventory Tracking On #
Quantity cannot be changed directly from:
- Product Edit
- Bulk Update
Use an inventory transaction instead.
This prevents the physical stock quantity from becoming different from its accounting inventory value.
12. Turning Inventory Tracking Off #
Inventory Tracking cannot be disabled while inventory remains.
Example:
Current Quantity: 20
Inventory Tracking: Yes
MESOS will not allow Inventory Tracking to be switched off immediately.
The inventory must first be reduced or adjusted to:
Quantity: 0
Once no inventory remains, Inventory Tracking can be disabled.
13. Inventory Tracking Summary #
| Inventory Tracking Off | Inventory Tracking On | |
|---|---|---|
| Track quantity | Yes | Yes |
| Warehouse stock | Yes, where applicable | Yes |
| Inventory Asset accounting | No | Yes |
| Inventory valuation | No | Yes |
| Weighted Average Cost | No | Yes |
| Starting quantity creates accounting opening balance | No | Yes, when quantity is above zero |
| Direct Product Edit quantity changes | Allowed for operational stock where supported | No |
| Bulk Update quantity | Operational updates where supported | No |
| Purchase affects inventory value | No inventory valuation | Yes |
| Sale creates COGS | No inventory COGS valuation | Yes |
| Can disable while stock remains | Not applicable | No |
14. Which Option Should I Use? #
Use Inventory Tracking Off if: #
You only need to know how many units are available and do not need the stock value maintained as an Inventory Asset.
Use Inventory Tracking On if: #
You need MESOS to manage:
- Stock quantity
- Inventory Asset value
- Weighted Average Cost
- Cost of Goods Sold
- Inventory accounting
Related Guides #
For step-by-step instructions, refer to:
Create Product & Service
Create a Product or Service manually.
Bulk Create Product & Service
Create multiple Products and Services using CSV.
Bulk Update Product & Service
Update existing Products and Services using CSV.