Working Capital Management: Where AP, AR and Inventory Meet

Introduction

Cash is not just on the income statement. It is in the time between paying a supplier and collecting from a customer. It is in the warehouse, sitting in inventory that has not yet sold. It is in the receivables ledger, representing revenue earned but not yet received. Working capital management is the discipline of systematically compressing these gaps so the business operates with less trapped cash and more liquidity for investment, debt reduction, or operational resilience.

In 2025, Deloitte’s Working Capital Roundup, which analyzed the financial performance of more than 2,300 companies, found that the cash conversion cycle shortened by about 0.9 days year over year across corporate markets. Gains came from reductions in Days Inventory Outstanding and extensions in Days Payable Outstanding, but Days Sales Outstanding rose as collection pressures persisted. The result: cash conversion improved, but unevenly, and for most companies the improvement reflected active short-term management rather than durable structural change.

That distinction matters for CFOs and Controllers who are building longer-term finance operations strategy. This blog explains where working capital improvement actually comes from, how AP, AR, and inventory interact, and which operational levers produce the most reliable results.

The Three Drivers of Working Capital: AP, AR, and Inventory

Working capital, in its simplest form, is current assets minus current liabilities. But the actionable version for a CFO is not the balance sheet formula. It’s understanding which operational activities tie up cash and for how long. Three activities dominate:

Accounts Payable (AP): The Liability Lever

AP represents money the company owes to suppliers for goods and services already received. From a working capital perspective, AP is a source of short-term financing. The longer a company holds cash before paying a supplier within agreed terms, the longer that cash is available for other uses. Days Payable Outstanding measures this.

DPO = (Accounts Payable / Cost of Goods Sold) × Number of Days

A higher DPO generally indicates better use of the supplier credit cycle. However, PwC’s global working capital research notes that using DPO as a quick fix is not sustainable: artificially stretching payment terms damages supplier relationships and, at scale, can increase supply chain risk to an unacceptable level.

Accounts Receivable (AR): The Asset Drag

AR represents money owed to the company by customers for goods and services already delivered. Every day a receivable sits uncollected is a day the company has funded a customer’s operations. Days Sales Outstanding measures this.

DSO = (Accounts Receivable / Revenue) × Number of Days

Deloitte’s 2025 analysis found that DSO rose across many sectors as collection pressures persisted, offsetting gains made on the DPO and DIO side. This is consistent with a broader pattern: AR is often where working capital improvement is most available but least pursued, because it requires cross-functional coordination between sales, finance, and customer service that payables-only strategies avoid.

Inventory: The Silent Cash Trap

For product businesses, inventory is frequently the largest single item on the current asset side of the balance sheet. Every unit sitting in a warehouse represents cash already spent on procurement, production, or logistics but not yet recovered through a sale. This is measured by Days Inventory Outstanding.

DIO = (Average Inventory / Cost of Goods Sold) × Number of Days

Deloitte’s 2025 roundup attributed some CCC improvement across corporate markets to lower DIO, as companies applied tighter inventory discipline in response to supply chain normalization after several years of elevated safety-stock build-up.

The Cash Conversion Cycle: How the Three Drivers Connect

The cash conversion cycle ties all three components into a single measure of operational cash efficiency:

Cash Conversion Cycle, CCC = DIO + DSO − DPO

Where:

• DIO (Days Inventory Outstanding) = how long cash is tied up in inventory before a sale
• DSO (Days Sales Outstanding) = how long cash is tied up in receivables after a sale
• DPO (Days Payable Outstanding) = how long the company defers paying its suppliers

A lower CCC means less cash is tied up in operations at any given time.

A negative CCC means the company collects from customers before it must pay suppliers (a powerful cash position).

The AFP defines the CCC as the net time funds are tied up in operating working capital, accounting for the turnover periods of inventory, accounts receivable, and accounts payable. It is the most operationally useful working capital metric for a CFO because it directly measures the impact of operational decisions, not just accounting positions.

For example, if a manufacturer buys raw materials on 30-day terms, takes 45 days to convert them to finished goods and sell them, and collects from customers in 60 days, then: DPO = 30, DIO = 45 and DSO = 60.

So, CCC = 45 + 60 − 30 = 75 days.

That means the company is funding 75 days of operations from its own cash before it sees the revenue return. If it can reduce DIO by 10 days through better demand planning, reduce DSO by 10 days through tighter collections, and extend DPO by 5 days through vendor negotiations, the CCC drops to 50 days, a 25-day improvement that directly reduces working capital requirements.

“The takeaway for CFOs is clear: resilience in 2026 will come from embedding working capital into operations, powered by better forecasting, automation, and stronger supplier collaboration.”

— Deloitte Working Capital Roundup 2025

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Why Working Capital Management Is Harder Than It Looks

Different teams control each of the three levers, measured by different systems, and optimized for different objectives. This is the core structural problem.

• AP is optimized for cash preservation, but the AP team’s daily work is often consumed by invoice processing, exception handling, and payment runs rather than strategic DPO management.
• AR is optimized for revenue collection, but sales teams are incentivized on bookings rather than cash conversion, and extended credit terms are routinely offered to close deals without accounting for their working capital cost.
• Inventory is optimized for service levels, but supply chain teams tend to hold buffer stock against demand uncertainty, especially after recent supply disruptions. Reducing inventory requires confidence in demand forecasting that many organizations have not yet built.

As a result, each function technically optimizes its own metric, but no one optimizes the CCC as a whole. In practice, working capital management requires a cross-functional finance governance layer that does not naturally exist in most organizations.

Recent research consistently points to a pattern across global companies: companies that focus primarily on payables extension as a working capital strategy eventually reach a ceiling, because DPO cannot be stretched indefinitely without supplier consequences. The more durable improvements come from DSO reduction through better receivables management and DIO reduction through supply chain efficiency, but these require more organizational coordination and longer timelines to execute.

The AP Team’s Specific Role in Working Capital Optimization

AP sits at the payables end of the CCC equation, and its impact on working capital goes well beyond simply paying invoices. When AP operates with precision, it creates the data infrastructure that makes strategic working capital management possible. When it operates reactively, it undermines the entire CCC calculation.

DPO Requires Clean Payables Data

You cannot manage DPO intentionally if you do not know, in real time, what is outstanding, what terms have been agreed with each supplier, and what the optimal payment timing is relative to those terms. A manual AP environment, where email and payment runs approve invoices by habit rather than strategy, makes DPO optimization practically impossible at scale.

Automated AP gives the finance team real-time visibility into the full payables position: what is due, when it is due, which suppliers offer early payment discounts, and which are approaching terms limits. That visibility is the prerequisite for any intentional working capital strategy on the payables side.

Early Payment Discounts Are a Working Capital Tool

When a supplier offers a 2/10 net 30 discount (2% discount for payment within 10 days, rather than the standard 30), the annualized return on taking that discount is approximately 36%. For a CFO, paying early is not always a working capital concession. If the cost of capital is below the annualized discount rate, taking the discount is the superior financial decision.

This calculation is only possible when the AP function has the visibility and control to act on discount windows before they close. That requires invoice capture at the point of receipt, fast approval workflows, and intentional payment scheduling rather than reactive responses. Manual AP processes routinely miss discount windows, creating a direct, calculable financial cost. The invoice approval workflow guide covers how to design an approval process fast enough to capture these opportunities.

The Connection Between Three-Way Matching and Cash Forecasting

Accurate cash forecasting, a prerequisite for working capital optimization, depends on knowing exactly which payables will clear and when. When AP invoices are matched to purchase orders and goods receipts through automated three-way matching, the outstanding payables position is reliable. When it is not, finance teams build forecast buffers that represent unnecessary cash reserves held against uncertainty. See how automated matching improves this in the three-way match guide.

Working Capital KPIs: What to Track and What They Tell You

For a deeper look at how AP-specific KPIs connect to broader finance metrics, see the AP KPIs and metrics guide.

Working Capital Optimization: Four Levers That Actually Work

Deloitte’s working capital research finds that the most resilient organizations improve the CCC through structural change rather than one-time tactical moves. These are the four structural levers with the most durable impact:

1. Automate AP to create intentional DPO management: replace a reactive payment process with one where every payable is visible, every discount window is tracked, and every payment is scheduled to optimize the balance between DPO extension and discount capture. This is structural, not tactical.
2. Tighten AR collections into a systematic workflow: DSO reduction requires a repeatable collections process, not ad-hoc reminders. Automated dunning, early payment incentives, and proactive dispute resolution all reduce DSO structurally.
3. Connect demand planning to inventory replenishment: DIO improvement requires that purchasing decisions are driven by current demand signals rather than historical safety stock rules. Integrating sales data with procurement triggers reduces the inventory cash trap without sacrificing service levels.
4. Build a cross-functional working capital dashboard: CCC management requires AP, AR, and supply chain teams to see the same metrics. A shared working capital dashboard that tracks DPO, DSO, DIO, and CCC weekly creates the organizational accountability needed for structural improvement.

How Serina Supports Working Capital Management Through AP Automation

AP automation is not just an efficiency initiative. It is a working capital management tool. When AP processes are fast, accurate, and data-rich, the payables side of the CCC becomes a strategic lever rather than a reactive back-office function.

Serina’s AP automation platform gives finance teams the real-time payables visibility, approval speed, and payment control they need to manage DPO intentionally, capture early payment discounts where they are financially beneficial, and produce the clean data that makes cross-functional CCC management possible.

If your AP team is spending more time processing invoices than managing payables strategy, that is a working capital problem with an operational solution.

Book a demo to walk through the working capital impact with your own numbers.

Conclusion

Working capital management is not a treasury exercise that happens quarterly. It is an operational discipline that plays out in AP, AR, and inventory workflows every day. The CFOs who manage the cash conversion cycle most effectively are the ones who have connected those three operational functions to a shared financial framework and given each team the visibility and systems to make decisions that serve the whole, not just their own metric.

For AP teams, the starting point is the same as it is for any working capital initiative: replace reactive processes with real-time visibility. The payables position is one of the most actionable levers on the CCC, and AP almost always runs below its potential when it relies on manual processes.

Find out how Serina turns AP into a working capital advantage

Frequently Asked Questions

What is working capital management and why does it matter for CFOs?

Working capital management is the process of optimizing the timing and efficiency of a company’s short-term assets (inventory, receivables) and liabilities (payables) to minimize the cash tied up in operations. It matters for CFOs because the cash conversion cycle directly affects liquidity, borrowing costs, and the company’s ability to invest and grow. A well-managed working capital position reduces the need for external financing and creates financial resilience.

What is the difference between DPO, DSO, and DIO?

DPO (Days Payable Outstanding) measures how long a company takes to pay its suppliers. DSO (Days Sales Outstanding) measures how long it takes to collect from customers after a sale. DIO (Days Inventory Outstanding) measures how long inventory sits before being sold. Together, they form the cash conversion cycle: CCC = DIO + DSO − DPO. All three must be managed together for working capital optimization to be durable.

How does accounts payable affect working capital?

AP directly controls DPO, the only CCC component that reduces cash tied up in operations. A higher DPO means the company is holding supplier cash longer before payment, improving short-term liquidity. However, extending DPO beyond agreed terms damages supplier relationships. Effective AP management optimizes DPO within contracted terms, captures early payment discounts where the annualized return exceeds the cost of capital, and provides the real-time payables data that makes cash forecasting accurate.

Is it better to have a high or low cash conversion cycle?

Lower is better. A lower CCC means less cash is trapped in operations between paying suppliers and collecting from customers. Some companies, particularly large retailers with strong bargaining power, achieve negative CCC values, meaning they collect from customers before they pay suppliers. For most businesses, the goal is to reduce the CCC progressively through structural improvements to all three components rather than through one-time tactics such as payment term stretching.

What is the most common mistake in working capital management?

The most common mistake is treating DPO extension as the primary working capital lever while neglecting DSO and DIO. Stretching payables as a quick fix is not sustainable and that the more durable opportunity sits in receivables and inventory management. A balanced approach that addresses all three components of the CCC produces more durable improvements and avoids the supplier relationship risk that DPO-only strategies create.