A manufacturer can have warehouses full of inventory and still stop production because one critical component is unavailable.

At first, this may seem contradictory.

If the company is holding significant inventory, why can it not fulfil its production requirements?

The reason is simple: total inventory value does not indicate whether the right materials are available at the right time.

A business may have excess quantities of slow-moving materials while urgently waiting for the component needed to complete an important production order.

This creates one of manufacturing’s most expensive problems:

Too much working capital is tied up in inventory, but production still faces material shortages.

More inventory does not always mean better availability

When manufacturers experience repeated shortages, the immediate response may be to purchase more materials or increase safety stock.

This can provide temporary protection, but it does not necessarily solve the underlying planning problem.

If demand, lead times, inventory records and production requirements are inaccurate, purchasing more stock can create additional excess without improving the availability of critical materials.

The business may then experience both problems simultaneously:

• Excess inventory occupying warehouse space
• Critical materials unavailable for production
• More working capital tied up in stock
• Urgent and expensive purchases
• Production orders delayed or rescheduled
• Customer deliveries affected
• Slow-moving or obsolete materials increasing

The objective should not be to hold the maximum possible inventory.

It should be to maintain the appropriate materials, quantities and timing required to support production and customer demand.

How do excess inventory and shortages happen together?

This situation is rarely caused by one issue. It normally develops through several disconnected planning decisions.

1. Demand changes, but purchasing plans do not

Customer demand can change quickly.

One product may sell faster than expected while demand for another product declines. If procurement continues working with outdated forecasts, the company may purchase materials for products that are no longer priorities while shortages develop elsewhere.

Manufacturers need a planning process that regularly connects customer demand, forecasts, current inventory and production requirements.

2. Lead times are inaccurate

The system may assume that a material can be delivered in ten days, while the supplier actually requires four weeks.

When planning parameters do not reflect operational reality, procurement proposals may be created too late.

The company may only discover the shortage after the production order is already approaching its start date.

3. Inventory records do not reflect physical stock

A system may show that sufficient material is available—but part of that stock may be damaged, blocked, reserved for another order or stored at a different location.

When planners cannot trust inventory information, they may create additional buffers outside the formal planning process.

This increases stock while reducing confidence in the system.

4. Bills of material are outdated

Material Requirements Planning depends on accurate product structures.

If a bill of material does not reflect the components currently required for production, the planning result will also be incorrect.

Engineering changes, alternative components and revised consumption quantities must be maintained consistently.

Otherwise, the company may procure materials that are no longer needed while failing to purchase the components currently required.

5. Safety stock is based on assumptions rather than risk

Safety stock is important when demand or supplier performance is uncertain.

However, the same policy should not automatically be applied to every material.

A low-value component with an unreliable supplier may require a different approach from an expensive material with stable demand and a dependable source.

When safety-stock levels are not reviewed regularly, they can gradually create excess inventory without protecting the materials that present the greatest production risk.

6. Departments work with different information

Sales may have the latest customer demand. Production may have a separate schedule. Procurement may work from exported spreadsheets, while inventory teams manage stock adjustments independently.

Each department may be making reasonable decisions based on the information available to it.

But if that information is not connected, the overall planning outcome can still be poor.

One missing component can delay the entire order

Consider a manufacturer producing industrial motors.

Each motor requires several materials, including metal components, bearings, wiring and fasteners.

The company may have sufficient quantities of almost every component. However, if one specific bearing is unavailable, the motor cannot be completed.

The production line may wait, the customer delivery may be delayed and other materials may remain unused.

The problem is not the company’s total inventory level.

The problem is material availability at the component, quantity, location and date level.

This is why manufacturing planning must look beyond warehouse value and ask:

• Which materials are required?
• How much is required?
• Where is the stock located?
• When will it be needed?
• Is the available quantity already committed?
• When can the supplier deliver?
• Which production and customer orders are at risk?

MRP connects demand with supply

Material Requirements Planning, or MRP, helps translate demand into procurement and production requirements.

It considers information such as:

• Customer requirements
• Planned demand
• Current inventory
• Existing purchase orders
• Planned and production orders
• Bills of material
• Procurement lead times
• Lot sizes
• Safety-stock levels
• Scheduled receipts

Based on this information, MRP can identify what should be produced or purchased and when it will be required.

However, MRP is not a replacement for reliable data and process ownership.

If lead times, bills of material, inventory balances or planning parameters are incorrect, the system can produce a technically valid plan that does not reflect business reality.

A successful MRP process therefore requires both suitable technology and disciplined master-data management.

Move from reviewing everything to managing exceptions

Production planners should not have to search through thousands of materials every day to identify potential problems.

A more effective approach is exception-based planning.

Instead of manually reviewing every material, planners can focus on issues that require action, such as:

• A material shortage affecting production
• A purchase order arriving after the requirement date
• Demand exceeding available supply
• A delayed production order
• Excess quantities beyond expected demand
• A requirement that should be rescheduled
• A critical material approaching a coverage problem

This allows planning teams to spend more time resolving important risks and less time comparing spreadsheets.

How SAP S/4HANA Cloud Public Edition can support planning

SAP S/4HANA Cloud Public Edition supports Material Requirements Planning to monitor stock and create procurement proposals for purchasing and production.

Manufacturers can schedule MRP runs regularly and use material-coverage applications to identify and analyse potential shortages.

The Manage Material Coverage application can help planners review coverage issues and take actions such as adjusting dates, changing quantities or processing relevant MRP elements.

This can support manufacturers in:

• Connecting demand with procurement and production
• Identifying material shortages earlier
• Monitoring material coverage
• Creating procurement proposals
• Prioritizing planning exceptions
• Reviewing requirements and available supply
• Responding to changes before production is interrupted

The value of these capabilities depends on the quality of the underlying planning information.

Technology can highlight an exception, but the organization must still define who owns the issue, what action should be taken and how quickly it must be resolved.

What should manufacturers review?

Before increasing inventory, manufacturers should investigate why shortages continue to occur.

Important questions include:

• Are demand forecasts updated regularly?
• Are supplier lead times accurate?
• Are inventory records reliable?
• Are bills of material current?
• Are safety-stock levels based on actual risk?
• Are purchase orders and production orders updated promptly?
• Can planners see stock across plants and storage locations?
• Are shortages identified before production begins?
• Who owns each type of planning exception?
• Are recurring shortage causes being tracked?

These questions help determine whether the real issue is insufficient inventory—or insufficient planning visibility and discipline.

The goal is not more inventory

A strong manufacturing-planning process does not attempt to eliminate every uncertainty by holding more stock.

It balances material availability, customer service, production continuity and working capital.

The objective is clear:

The right material, in the right quantity, at the right location and at the right time.

When demand, procurement, inventory and production operate through a connected process, manufacturers can identify risks earlier and make better-informed decisions.

At RS Integrators, we help industrial manufacturers connect planning, procurement, production, inventory, sales and finance through SAP S/4HANA Cloud Public Edition.

Our focus is on creating standardized and connected processes that improve material visibility, support exception-based planning and build a stronger foundation for manufacturing growth.

Before purchasing more inventory, manufacturers should ask:

Do we really have a stock problem—or do we have a planning problem?