The neverending challenge in inventory management lies in maintaining well-stocked shelves and ensuring the seamless operation of your supply chain.
A key aspect of this undertaking is understanding and calculating “gross requirements.” The gross requirements represent the overall amount of a product or service required to satisfy customer needs.
Proficiency in comprehending and computing these requirements is necessary to guarantee your business maintains adequate inventory levels to fulfill customer demand. Read on to know more about it.
This blog post will discuss gross requirements, examples, formulas, and how to calculate them. It will also explore some factors that can impact gross requirements, such as seasonality and changes in customer demand.
What is the gross requirement?
Gross requirements encompass both independent and dependent demands for a component, calculated prior to adjusting for on-hand inventory and scheduled receipts.
It represents the aggregate need for raw materials, additional components, and subassemblies necessary to manufacture a specific item.
It combines elements from both dependent and independent demands, considering the availability of each in the overall assessment.
The dependent demand is processed or unprocessed items through the production line. In contrast, independent demands come from external market factors, which dictate what will ultimately become of your finished goods once you’ve completed all processes involved in creating them.
How is it evaluated?
We calculate and fix the gross requirements before netting the on-hand inventory or subtracting the demands based on the scheduled receipts.
It is the minimum inventory required to keep the firm running smoothly. It does not consider the availability of raw materials in the inventory or any predetermined evaluation of scheduled receipts.
How to calculate gross requirements?
Gross requirements are a quantity, not a cost. For a given item and time period, you add up every source of demand for that item, before looking at inventory or incoming supply:
Gross requirements (per period) = independent demand + dependent demand
- Independent demand comes from the master production schedule (MPS), sales forecasts, and customer orders for the finished item.
- Dependent demand comes from the bill of materials (BOM) explosion: each parent item’s planned order is multiplied by how many of this component go into it, then time-shifted by the parent’s lead time.
In Material Requirements Planning (MRP), you record these totals period by period on the item’s planning record. Only after the gross requirements are set do you net out on-hand inventory and scheduled receipts to find the net requirements.
Examples
Example 1
A thermal plant’s total amount of input can be termed its gross requirement.
The thermal plant will measure it in tons of coal required at the end of each periodic productive cycle.
Example 2
The total amount of flour required to produce, say, 40 pieces of bread at a roadside food joint would be its gross requirement.
The above is done without considering,
- The leftover materials from the previous month or
- Any orders placed beforehand that are scheduled to arrive
Worked example: gross requirements in an MRP record
A bicycle maker plans production for the next five weeks, and every bicycle uses two wheels. The wheel is a dependent-demand component, so exploding the bicycle schedule through the BOM gives the wheel’s gross requirements. The item starts with 120 wheels on hand and has one scheduled receipt of 100 arriving in Week 1 (lot-for-lot ordering, one-week lead time):
| Wheel component | Wk 1 | Wk 2 | Wk 3 | Wk 4 | Wk 5 |
| Gross requirements | 200 | 150 | 300 | 0 | 250 |
| Scheduled receipts | 100 | – | – | – | – |
| Projected on-hand (start 120) | 20 | 0 | 0 | 0 | 0 |
| Net requirements | 0 | 130 | 300 | 0 | 250 |
| Planned order receipt | – | 130 | 300 | – | 250 |
| Planned order release (1-wk lead) | 130 | 300 | – | 250 | – |
The gross requirements row is the starting point: the raw demand for wheels, 200 + 150 + 300 + 250 = 900 across the horizon. Notice it ignores the 120 on hand and the 100 scheduled receipt. Only after netting those out do we get the net requirements (0, 130, 300, 0, 250), which drive the planned orders. In Week 1, gross requirements are 200, but because 120 + 100 = 220 units are available, the net requirement is 0.
Gross requirements vs net requirements
| Gross requirements | Net requirements | |
| What it is | Total demand for an item in a period | What is left to order after available supply |
| Counts on-hand inventory? | No | Yes |
| Counts scheduled receipts? | No | Yes |
| How it is found | Independent demand + dependent demand | Gross requirements − on-hand − scheduled receipts + safety stock |
| Week 2 in the example | 150 | 130 |
Factors that impact gross requirements
Seasonality
Many businesses experience fluctuations in customer demand throughout the year. For instance, a clothing retailer may see higher demand for winter coats in the colder months.
Understanding these seasonal patterns is crucial for accurately calculating gross requirements.
Changing Customer Demand
Customer preferences and demand can shift suddenly due to various factors, such as trends, marketing campaigns, or external events. Keeping a close eye on market dynamics helps in anticipating and accommodating changes in gross requirements.
Lead Time
The time it takes for your suppliers to deliver products can impact your gross requirements. Longer lead times may necessitate higher safety stock levels to bridge supply gaps.
Calculate Lead time demand using our Online Lead Time Demand Calculator
Supplier Reliability
The reliability of your suppliers can significantly influence your gross requirements. Frequent delays or quality issues might prompt you to maintain larger safety stock quantities to mitigate supply chain disruptions.
Economic Order Quantity (EOQ)
Economic Order Quantity (EOQ) is a calculation that helps determine the ideal order quantity to minimize total inventory costs. Optimizing your EOQ can impact both safety stock and gross requirements.
Beyond these factors, it’s essential to keep an eye on demand forecasting accuracy, technology adoption (like advanced inventory management software), and ongoing data analysis.
You can calculate EOQ using our Economic Order Quantity Calculator and use our Safety Stock Calculator to check safety stock inventory.
Why are gross requirements essential to figure out?
A firm needs to figure out its gross requirements capacity before operating. It is the amount of raw material the firm can function with at its full potential.
Based on the gross amount required, the firm can easily calculate the amount of on-hand inventory and other inventories based on rising demand.
If a company has a clear idea of the gross amount required to function, the company can cut down costs based on storage.
That gives an idea of the on-hand inventory required to avoid running a risk of massive loss due to loss of demand.
Similarly, due to loss of supply, a firm can lose out on customers if it is not stocked sufficiently for the future.
What is the gross material requirements plan in manufacturing?
The gross requirements planning process in manufacturing determines the number of units that need to be produced to meet customer demand. This process begins with a forecast of customer demand, which is then used to create a production plan.
The production plan considers the available inventory, the lead time for production, and the desired levels of safety stock. From this information, you can calculate the gross requirements.
The gross requirements will typically be higher than the actual customer demand, including an allowance for production losses and planned sales promotions.
Once the gross requirements are known, you can use them to generate a production schedule. This schedule is then used to determine the necessary raw materials and components, which are procured to support the manufacturing process.
Finally, the finished goods are produced and shipped to customers. By following this process, manufacturers can ensure that they have the necessary resources to meet customer demand without incurring unnecessary costs.
Characteristics of gross requirements
- Gross requirements are time-phased: they are stated for each planning period (day, week, or month) and shift as the master schedule and forecasts change.
- They are demand-driven: the higher the demand for the finished product, the higher the gross requirements for its components and raw materials.
- They are the starting point of MRP: netting on-hand inventory and scheduled receipts against them produces the net requirements that trigger planned orders.
FAQs
What is the gross material requirements formula?
Gross requirements for an item equal its independent demand (from the master production schedule, forecasts, and customer orders) plus its dependent demand (from exploding the bills of materials of its parent items).
It is a quantity for each time period, calculated before subtracting on-hand inventory or scheduled receipts.
How do we find gross requirements in MRP?
In MRP, gross requirements come from demand, not from price. For a finished item they come from the master production schedule and customer orders; for a component they come from the BOM explosion of every parent item’s planned orders, offset by lead time.
You total these quantities for each period on the item’s MRP record.
What is the difference between a gross requirement and a net requirement?
Net requirements are requirements for a product based on its gross requirements minus on-hand stock and scheduled receipt.
A net requirement plan adjusts for on-hand inventory and scheduled receipt at each level, whereas a gross requirement plan is a plan that shows the total demand for a product and it also shows when production should start to meet its requirements.
Most manufacturing industries are about maintaining the balance between the gross and net requirements and keeping in mind the on-hand inventories and scheduled receipts.
Striking a balance is very important and key to a thriving industry.
Conclusion
To sum up, gross requirements represent the total units needed by customers or retailers. This calculation includes units sold and the additional quantity for pending orders yet to be fulfilled.
Companies rely on gross requirements to predict demand, assessing both immediate and future inventory needs. This evaluation helps them understand current stock levels, empowering effective planning for future demands. Hope this post has offered you a clearer understanding of this concept.