Working Capital Optimization: DSO, DPO, DIO, Cash Conversion Cycle, and a 90 Day Plan
NMS Consulting resources
Working capital optimization is about freeing cash without starving the business. The biggest opportunities usually sit in receivables, inventory, payables, and the everyday operating decisions that shape them. Done well, the work improves cash conversion while protecting sales, supplier relationships, service levels, and growth.
What is working capital optimization?
Working capital optimization is the disciplined management of receivables, inventory, payables, and related operating processes so the business uses no more cash than it needs to run well.
It is not simply a finance exercise. Sales teams influence customer payment terms. Operations and supply chain determine inventory levels. Procurement negotiates supplier terms. Finance sees the result, but many of the decisions that create or release cash happen somewhere else.
That is why the best working capital programs are cross functional. Finance provides the baseline and measurement. Commercial, procurement, supply chain, operations, and technology teams change the behaviors and processes that actually move cash.
McKinsey reported in October 2026 that companies can often release meaningful cash from working capital, with some improvements visible within 60 to 90 days. Its analysis also notes that the right target depends on industry, geography, growth, and business model rather than one universal benchmark. Read McKinsey’s 2026 working capital analysis.
This article is a management resource. Accounting treatment, tax, lending agreements, legal obligations, supplier contracts, customer contracts, and regulated activities should be reviewed by qualified specialists where relevant.
The cash conversion cycle shows where cash gets tied up
The cash conversion cycle, often shortened to CCC, measures how long cash is tied up between paying for goods or services and collecting cash from customers. It combines three familiar measures: days inventory outstanding, days sales outstanding, and days payable outstanding.
| Metric | What it measures | Typical direction |
|---|---|---|
| DSO | How long it takes to collect cash after a sale is recorded. | Lower is usually better, provided collections do not damage customer relationships or revenue. |
| DIO | How long inventory sits before it is sold or consumed. | Lower can release cash, but inventory should still support service, production, and resilience. |
| DPO | How long the company takes to pay suppliers. | Higher can preserve cash, but overly aggressive terms can hurt suppliers, pricing, or continuity. |
| Cash conversion cycle | The net number of days cash is tied up across receivables, inventory, and payables. | Shorter generally means less cash is tied up in operations. |
A shorter cash conversion cycle is not automatically better in every situation. A fast growing company may need more inventory. A strategic supplier may deserve faster payment. A large customer may require longer terms. The goal is not to push every metric to an extreme. The goal is to remove avoidable cash drag.
Deloitte’s current working capital research describes order to cash, forecast to fulfill, and procure to pay as the three main operating cycles that shape working capital performance. See Deloitte’s working capital overview.
DSO, DPO, DIO, and cash conversion cycle formulas
These formulas are useful for executive reporting, but they should be paired with transaction level analysis. A company can have an acceptable average while still carrying overdue invoices, obsolete stock, or inconsistent supplier terms.
| Metric | Formula | What to watch |
|---|---|---|
| DSO | Accounts receivable divided by credit sales, multiplied by days in the period. | Use consistent sales definitions and account for seasonality. |
| DIO | Average inventory divided by cost of goods sold, multiplied by days in the period. | Inventory mix, obsolescence, safety stock, and demand volatility matter. |
| DPO | Accounts payable divided by purchases or cost of goods sold, multiplied by days in the period. | Purchases are preferable when reliable data is available. |
| Cash conversion cycle | DSO plus DIO minus DPO. | Use it as a directional measure, then investigate the drivers underneath it. |
| Net working capital | Current operating assets minus current operating liabilities, using the company’s agreed definition. | Define clearly which cash, debt, tax, and other items are included or excluded. |
Keep the definitions stable. If one business unit calculates DSO from revenue and another uses credit sales, the comparison will be noisy. Finance should own the metric definitions and the baseline used for improvement targets.
A working capital diagnostic should go below the headline ratios
The first step is not to tell every function to improve its metric by ten percent. Start by finding where cash is actually stuck and why.
| Area | Questions to ask | Data to review |
|---|---|---|
| Receivables | Are payment terms inconsistent? Are invoices late or wrong? Are disputes unresolved? Are collections focused on the right accounts? | Invoice aging, customer terms, dispute codes, billing errors, collection notes, credit limits, and payment history. |
| Inventory | Which items are slow moving? Where is safety stock too high? Are forecasts reliable? Are minimum order quantities driving excess? | SKU inventory, demand history, forecast error, lead times, service levels, obsolescence, batch sizes, and supplier constraints. |
| Payables | Are suppliers being paid earlier than agreed? Are negotiated terms actually used? Are terms inconsistent across similar suppliers? | Payment dates, contract terms, invoice dates, purchase orders, supplier category, early payment discounts, and exceptions. |
| Cash forecasting | Can the company see short term cash needs early enough to act? | Receipts, disbursements, payroll, debt service, taxes, capex, inventory purchases, and forecast accuracy. |
| Governance | Who owns working capital across functions? Are incentives aligned with cash? | KPIs, bonus plans, policy exceptions, approval rights, review cadence, and executive accountability. |
Deloitte recommends transaction level analytics, benchmarking, root cause analysis, quick wins, structural changes, and a working capital dashboard rather than relying only on top level ratios. See Deloitte’s approach.
Accounts receivable: lower DSO by fixing the process before chasing harder
Collections matter, but DSO often starts moving long before the collections team gets involved. Sales may agree extended terms. Contracts may be incomplete. Customer setup may be wrong. Invoices may go out late. A billing error can add weeks to payment.
| Lever | Example action |
|---|---|
| Payment terms | Set clear term guardrails by customer segment, deal size, risk, and commercial value. |
| Contract to billing handoff | Make sure billing requirements, purchase order needs, tax details, and customer portals are known before service starts. |
| Invoice speed | Reduce the time between delivery, acceptance, milestone completion, and invoice creation. |
| Invoice accuracy | Track root causes of credits, rebills, pricing errors, missing information, and rejected invoices. |
| Dispute management | Give disputes an owner, reason code, target resolution date, and escalation route. |
| Collections | Segment accounts by value, risk, aging, payment behavior, and likelihood of recovery. |
| Sales incentives | Avoid rewarding revenue without any consideration of payment quality or commercial terms. |
Deloitte notes that high DSO can begin with sales terms, billing errors, and weak process discipline rather than collections alone. Read Deloitte’s order to cash discussion.
Inventory: free cash without creating empty shelves
Inventory is usually the hardest working capital lever because the wrong cut can create missed sales, production disruption, or poor service. The answer is not a blanket reduction. It is better segmentation and better decisions.
| Lever | What to examine |
|---|---|
| SKU segmentation | Separate high velocity, strategic, volatile, seasonal, slow moving, and obsolete items. |
| Safety stock | Reset safety stock using service targets, lead time variability, demand variability, and supply risk. |
| Forecast quality | Track forecast error at the level where inventory decisions are actually made. |
| Order quantities | Review minimum order quantities, batch sizes, production economics, and supplier constraints. |
| Lead time | Reduce avoidable supplier, manufacturing, transport, approval, and planning delay. |
| Slow moving stock | Create clear rules for markdown, redeployment, return, substitution, consumption, or disposal. |
| Portfolio complexity | Identify low volume products and variants that consume disproportionate inventory. |
McKinsey cautions that inventory improvement usually takes longer than receivables or payables because companies need to address underlying demand and operating issues without hurting availability. Read McKinsey’s 2026 analysis.
For supply chain related work, see NMS Consulting’s supply chain risk management consulting.
Accounts payable: improve DPO without treating suppliers like a bank
Payables can release cash quickly, but blunt payment delays can damage suppliers, increase prices, or create supply risk. The better question is whether the company is using the terms it has negotiated and whether those terms make sense by supplier category.
| Lever | Example action |
|---|---|
| Terms strategy | Set target payment terms by supplier segment, category, market practice, bargaining position, and risk. |
| Contract compliance | Find suppliers being paid earlier than contract terms require. |
| Term consistency | Compare similar suppliers with materially different terms and investigate why. |
| Invoice process | Reduce late approvals, missing purchase orders, duplicate invoices, and manual exceptions. |
| Discounts | Compare the return from early payment discounts with the value of keeping cash longer. |
| Supplier finance | Consider approved financing structures where they support both buyer liquidity and supplier economics. |
| Supplier risk | Protect strategically important or financially fragile suppliers from terms that create unacceptable supply risk. |
Deloitte’s working capital guidance points to supplier terms, payment timing, purchase order discipline, and payment process controls as common areas of opportunity. See Deloitte’s procure to pay discussion.
For related sourcing work, see NMS Consulting’s procurement consulting for reducing costs.
How to estimate the cash released from working capital improvements
A useful first estimate translates days into dollars. It is not the final business case, but it helps leaders see where the biggest opportunities may sit.
| Area | Illustrative calculation |
|---|---|
| Receivables | Annual credit sales divided by 365, multiplied by the DSO reduction in days. |
| Inventory | Annual cost of goods sold divided by 365, multiplied by the DIO reduction in days. |
| Payables | Annual purchases divided by 365, multiplied by the DPO increase in days. |
| Total gross cash release | Receivables release plus inventory release plus payables release. |
Illustrative example
Assume a company has $365 million of annual credit sales, $219 million of annual cost of goods sold, and $182.5 million of annual purchases. A five day DSO improvement would release about $5 million. A seven day DIO improvement would release about $4.2 million. A four day DPO improvement would release about $2 million. The gross illustrative cash release would be about $11.2 million before implementation costs, taxes, seasonality, business growth, and other adjustments.
Do not present this as guaranteed cash. Some changes may already be embedded in forecasts. Some customers or suppliers may not be movable. Inventory reductions may require investment elsewhere. Finance should validate the final opportunity and the treatment of recurring versus one time benefits.
McKinsey’s October 2026 analysis says focused diagnostics can surface one time cash opportunities equal to roughly 10 to 30 percent of the working capital base in some situations, but the result depends on the company and where cash is tied up. Read the McKinsey analysis.
Working capital needs one owner, but many functions must act
Working capital can become everyone’s concern and nobody’s job. A named leader or working capital office can coordinate the program, but the operating functions still need to own the changes.
| Role | Primary responsibility |
|---|---|
| CFO or executive sponsor | Sets ambition, resolves tradeoffs, approves targets, and keeps cash visible alongside revenue and margin. |
| Working capital lead | Coordinates receivables, inventory, payables, analytics, initiatives, and executive reporting. |
| Finance | Owns definitions, baselines, cash release validation, forecasts, and reporting. |
| Sales | Owns commercial terms, customer behavior, contract discipline, and escalation of payment issues. |
| Supply chain and operations | Own inventory policy, planning, service levels, lead times, production, and obsolescence. |
| Procurement | Owns supplier terms, category strategy, supplier risk, and contract compliance. |
| Technology and data | Provides transaction visibility, workflow automation, forecasting, alerts, and data quality. |
McKinsey recommends assigning clear working capital coordination while keeping decisions close to the business teams that create the cash impact. See McKinsey’s governance discussion.
Where AI and automation can help working capital
AI is most useful when it helps teams spot the next decision earlier. The value comes from better action, not from adding another dashboard.
| Area | Potential use |
|---|---|
| Receivables | Predict likely late payments, prioritize collections, identify dispute patterns, and detect term mismatches. |
| Inventory | Improve demand forecasts, flag slow moving stock, model safety stock, and identify unusual inventory build. |
| Payables | Find early payments, inconsistent terms, duplicate invoices, missed discounts, and processing exceptions. |
| Cash forecasting | Use transaction patterns and operating data to improve short term receipt and disbursement forecasts. |
| Root cause analysis | Group recurring invoice, collection, inventory, and payment issues so teams can fix the process rather than treat symptoms. |
McKinsey notes that AI can help identify payment term mismatches, predict late invoices, and improve demand forecasting. Deloitte’s current finance research also identifies working capital optimization as one of the areas where finance leaders see meaningful opportunity from agentic systems. Read McKinsey’s analysis. See Deloitte’s 2026 finance trends.
For implementation support, see NMS Consulting’s AI implementation and usage consulting and data and technology consulting.
Example 90 day working capital optimization plan
Ninety days is enough to find the main cash opportunities, launch quick actions, and set up ownership. It is not enough to fix every inventory or operating model issue, so the plan should separate immediate cash actions from structural work.
| Period | Focus | Expected outputs |
|---|---|---|
| Days 1 to 15 | Baseline the cash. | Metric definitions, working capital baseline, aging, inventory segmentation, supplier terms view, cash forecast, and governance. |
| Days 16 to 30 | Find the root causes. | Customer term analysis, invoice issues, dispute causes, slow moving inventory, forecast gaps, supplier term exceptions, and quick wins. |
| Days 31 to 45 | Size the opportunities. | Cash release estimates, risk adjustments, initiative owners, cost to implement, dependencies, and customer or supplier impact. |
| Days 46 to 60 | Launch fast actions. | Collections focus, billing fixes, dispute backlog actions, payment term compliance, selected sourcing actions, and inventory clean up. |
| Days 61 to 75 | Start structural changes. | Policy updates, process redesign, planning changes, system fixes, supplier negotiations, forecast improvements, and incentive changes. |
| Days 76 to 90 | Make it part of management. | Executive dashboard, weekly or monthly cadence, finance validated cash release, KPI owners, unresolved issues, and the next wave of initiatives. |
Deloitte’s working capital guidance follows a similar logic: make performance visible, create urgency, turn opportunities into a roadmap, then build governance and tracking so improvements hold. See Deloitte’s approach.
If liquidity is already tight, the NMS 13 week cash flow template can sit alongside the working capital program.
Working capital KPIs that tell management what is actually changing
The headline ratios matter, but the operating measures underneath them tell leaders where to act.
| KPI | What it shows |
|---|---|
| DSO | Overall speed of converting receivables into cash. |
| Past due receivables | Share and value of invoices beyond agreed customer terms. |
| Billing cycle time | Time between delivery or acceptance and invoice issuance. |
| Dispute aging | How long unresolved customer disputes are delaying payment. |
| DIO | Overall amount of inventory carried relative to demand or cost of sales. |
| Slow moving and obsolete inventory | Cash tied up in inventory with weak expected demand or limited use. |
| Forecast accuracy | How reliably demand forecasts support inventory and production decisions. |
| DPO | Overall timing of supplier payments. |
| Early payment leakage | Payments made before agreed terms without an intentional economic reason. |
| Working capital cash release | Finance validated cash released from approved initiatives. |
| Cash conversion cycle | Combined direction of receivables, inventory, and payables. |
| Cash forecast accuracy | How closely short term forecast cash flows match actual receipts and payments. |
Deloitte’s 2026 working capital roundup argues that durable improvement comes from embedding working capital into operations rather than relying on quarter end actions. Read Deloitte’s 2026 working capital priorities.
Common working capital mistakes
-
Giving finance the target while leaving sales, procurement, and supply chain incentives unchanged.
-
Using a company wide DSO target without looking at customer terms, disputes, billing errors, and payment behavior.
-
Cutting inventory across the board instead of separating healthy stock from slow moving, obsolete, seasonal, and strategic inventory.
-
Stretching suppliers without considering supplier health, market power, service, continuity, or price tradeoffs.
-
Improving quarter end cash with temporary actions that reverse the following month.
-
Counting forecast movement as cash release before finance can trace it to an approved working capital initiative.
-
Ignoring growth. A growing business may need more working capital even when its underlying efficiency is improving.
-
Automating a broken billing, collections, planning, or payables process without fixing the root cause first.
-
Managing DSO, DIO, and DPO separately even though customer, supplier, and inventory decisions interact.
Common questions about working capital optimization
What is working capital optimization?
Working capital optimization is the management of receivables, inventory, payables, and related operating processes so the business uses no more cash than it needs to operate effectively.
What is the cash conversion cycle formula?
The cash conversion cycle is DSO plus DIO minus DPO. It estimates how long cash is tied up between paying for inputs and collecting cash from customers.
How can a company reduce DSO?
Common actions include tightening payment term discipline, sending invoices faster, reducing billing errors, resolving disputes earlier, improving customer setup, segmenting collections, and aligning sales incentives with payment quality.
How can a company reduce inventory without hurting service?
Segment inventory, improve demand forecasts, reset safety stock, reduce lead times, review minimum order quantities, address slow moving stock, and simplify low value product complexity. Avoid blanket reductions that ignore service and supply risk.
How can a company improve DPO?
Start by using negotiated supplier terms consistently, correcting early payments, improving purchase order and invoice processes, reviewing term differences across similar suppliers, and renegotiating terms where the commercial relationship supports it.
How much cash can working capital optimization release?
The answer depends on the starting point, industry, growth, seasonality, customer mix, supplier base, inventory model, and operating constraints. McKinsey’s 2026 analysis says focused diagnostics can identify one time cash opportunities equal to roughly 10 to 30 percent of the working capital base in some companies, but this should not be treated as a universal target.
How quickly can working capital improve?
Receivables and payables can move within weeks or a quarter when the problem is terms, billing, collections, or payment timing. Inventory usually takes longer because planning, supply, production, and service levels need to change without disrupting the business.
Can AI improve working capital?
Yes. Useful applications include predicting late payments, prioritizing collections, improving demand forecasts, finding payment term mismatches, identifying slow moving inventory, and improving short term cash forecasts. The value comes from better decisions and follow through, not the technology alone.
Who should own working capital?
The CFO usually sponsors the effort, but working capital should not sit inside finance alone. Sales, procurement, supply chain, operations, and finance all make decisions that affect cash. A named working capital lead can coordinate the program across those teams.
Sources
The external sources below support the current working capital, cash conversion, finance, and automation principles used in this article. The formulas, diagnostic tables, KPI definitions, and 90 day roadmap are NMS Consulting’s management tools and should be adapted to the company.
- McKinsey: The cash hiding in plain sight. October 2026 analysis of working capital, cash conversion, cash release, governance, data, and AI.
- Deloitte: Working Capital Roundup. Priorities for 2026, cash conversion, forecasting, automation, supply chain finance, and structural working capital improvement.
- Deloitte: Optimizing Working Capital. Order to cash, forecast to fulfill, procure to pay, diagnostics, roadmaps, governance, and dashboards.
- Deloitte: How to Improve Working Capital. Tactical, capability, and structural working capital improvement paths.
- PwC: Future of Finance 2026. Cash flow, working capital, automation, data, AI, and finance operating model priorities.
- Deloitte Insights: Finance trends and leadership. 2026 finance priorities and agentic AI opportunities, including working capital optimization.
