What is Purchase Quantity Variance (PQV)?
Purchase Quantity Variance (PQV) measures the difference between the standard quantity of materials expected to be purchased and the actual quantity purchased, expressed in monetary terms using the standard purchase price.
It helps businesses understand whether they purchased more or fewer materials than originally planned and evaluates the financial impact of that difference.
For example, a manufacturer plans to purchase 10,000 kg of raw material for production but ends up purchasing 11,000 kg. If the additional quantity was not planned, the finance and procurement teams investigate the reason for the variance.
PQV is commonly used in manufacturing, procurement, and cost accounting to monitor purchasing efficiency and inventory planning.
How Does Purchase Quantity Variance Work?
Businesses prepare production plans and estimate the quantity of raw materials required.
After procurement, the actual quantity purchased is compared with the planned quantity.
The process generally follows these steps:
Production Planning → Standard Quantity Determined → Materials Purchased → Actual Quantity Compared → Purchase Quantity Variance Calculated → Variance Investigated
A significant variance may indicate issues with demand forecasting, inventory planning, or purchasing decisions.
Purchase Quantity Variance Formula
The formula for Purchase Quantity Variance is:
Purchase Quantity Variance = (Actual Quantity Purchased − Standard Quantity) × Standard Purchase Price
For example:
| Particular | Value |
|---|---|
| Standard Quantity | 8,000 units |
| Actual Quantity Purchased | 8,500 units |
| Standard Price | ₹50 per unit |
PQV = (8,500 − 8,000) × ₹50
PQV = ₹25,000 (Unfavorable)
The business purchased 500 more units than planned, increasing procurement costs by ₹25,000 based on the standard price.
Example of Purchase Quantity Variance
A beverage manufacturer estimates that it needs 15,000 plastic bottles for monthly production.
However, the procurement team purchases 16,200 bottles.
| Particular | Amount |
|---|---|
| Standard Quantity | 15,000 units |
| Actual Quantity | 16,200 units |
| Standard Price | ₹12 per bottle |
| Purchase Quantity Variance | ₹14,400 Unfavorable |
The additional purchase may have resulted from bulk buying, inaccurate demand forecasting, or higher expected production.
Finance and procurement teams review the reason to determine whether the variance was justified.
Favorable vs. Unfavorable Purchase Quantity Variance
Purchase Quantity Variance can be either favorable or unfavorable depending on whether actual purchases are lower or higher than planned.
| Favorable PQV | Unfavorable PQV |
|---|---|
| Actual quantity purchased is lower than the standard quantity | Actual quantity purchased exceeds the standard quantity |
| May reduce inventory carrying costs | May increase inventory holding costs |
| Indicates efficient purchasing if production requirements are met | May indicate overstocking or poor planning |
However, a favorable variance is not always positive. Purchasing too little inventory can lead to production delays or stock shortages.
Common Causes of Purchase Quantity Variance
Several operational factors can create quantity variances.
Some of the most common include:
- Inaccurate demand forecasting
- Overstocking
- Emergency purchases
- Minimum order quantity requirements
- Supplier bulk discount offers
- Changes in production schedules
- Seasonal demand fluctuations
- Inventory replenishment errors
- Safety stock adjustments
Understanding the cause of the variance is more valuable than simply measuring it.
Why is Purchase Quantity Variance Important?
Monitoring PQV helps businesses improve procurement planning and inventory management.
It enables organizations to:
- Evaluate purchasing decisions.
- Improve demand forecasting.
- Reduce excess inventory.
- Optimize working capital.
- Monitor procurement efficiency.
- Support production planning.
- Identify inventory planning issues.
When reviewed alongside other procurement metrics, PQV provides valuable insights into purchasing performance.
Purchase Quantity Variance vs. Purchase Price Variance
Although both metrics evaluate procurement performance, they measure different aspects of purchasing.
| Purchase Quantity Variance | Purchase Price Variance |
|---|---|
| Measures difference in quantities purchased | Measures difference in purchase prices |
| Focuses on inventory planning | Focuses on procurement cost |
| Uses standard price for calculation | Uses purchased quantity for calculation |
| Indicates over- or under-purchasing | Indicates paying more or less than expected |
Organizations often analyze both metrics together to gain a complete understanding of procurement performance.
How Businesses Reduce Purchase Quantity Variance
Businesses can minimize unnecessary quantity variances by:
- Improving demand forecasting.
- Reviewing production plans regularly.
- Maintaining optimal inventory levels.
- Monitoring inventory turnover.
- Using data-driven replenishment planning.
- Coordinating procurement with production schedules.
- Reviewing supplier minimum order requirements.
The objective is to purchase the right quantity at the right time while avoiding both stock shortages and excess inventory.
Frequently Asked Questions
Is Purchase Quantity Variance always unfavorable?
No. Purchasing more than planned generally creates an unfavorable variance because it increases inventory investment. However, purchasing additional inventory may be beneficial if it supports future demand, secures bulk discounts, or protects against supply shortages.
Who monitors Purchase Quantity Variance?
PQV is commonly monitored by procurement teams, inventory planners, finance departments, cost accountants, and manufacturing managers to evaluate purchasing efficiency and inventory planning.
What causes high Purchase Quantity Variance?
Large variances are often caused by inaccurate demand forecasts, unexpected changes in production requirements, supplier minimum order quantities, emergency purchases, or inventory planning errors.
What is the difference between Purchase Quantity Variance and Material Usage Variance?
Purchase Quantity Variance measures whether the business purchased more or fewer materials than planned. Material Usage Variance measures whether production consumed more or fewer materials than the standard quantity required. One focuses on procurement decisions, while the other evaluates manufacturing efficiency.