A Purchase Order does not remain static from the day it is confirmed until the day it is delivered.
Demand changes. Production plans move. Inventory positions change. Customers change priorities. Suppliers experience capacity constraints. Materials become unavailable. Delivery dates need to move.
For the operative buyer, this means that managing an open Purchase Order is not simply a matter of waiting for delivery.
The buyer needs to keep the order aligned with the latest valid requirement and the latest supplier commitment.
The important issue is therefore not whether Purchase Orders change.
Change is normal.
The important question is:
When something changes, is the change identified, communicated, confirmed, resolved and correctly reflected in the purchasing system?
This article explains how to measure that process using the PO Change Control Rate, supported by change lead time, backlog, ageing, reason codes and supplier-response measures.
LHTS Procurement Framework
Primary role: Operative Procurement
Supporting interfaces: Planning / Supplier / Tactical Procurement / Production
Procurement process: Open Order Management / Purchase Order Change Management / Procure-to-Pay
Learning level: Basic
Related course: Operative Procurement Processes 1-3
This article is part of the LHTS Operative Buyer KPI system.
The common principle behind the system is:
Each KPI should measure a process the operative buyer is expected to control or coordinate, identify operational problems early and lead to a defined action.
For Active PO Management, the core question is:
When an open Purchase Order needs to change, does procurement keep the change under control and maintain a reliable view of the latest agreed supplier commitment?
Quick answer: What does the Active PO Management KPI measure?
The recommended headline KPI is:
PO Change Control Rate
PO Change Control Rate (%) = Eligible PO change events correctly processed or brought under control within SLA ÷ Total eligible PO change events due for control × 100
A PO change event is considered under control when the operative buyer has:
- identified or received the change;
- validated that the request is actionable;
- communicated the change to the supplier where required;
- obtained or followed up the supplier response;
- resolved or escalated any difference;
- updated the purchasing system to reflect the latest agreed position.
The supplier does not need to accept every requested change for the buyer’s internal KPI to succeed.
The operative buyer is measured on controlling the process, not on forcing the supplier to accept something it cannot support.
Why Active PO Management matters
A confirmed Purchase Order represents the current purchasing position between buyer and supplier.
But that position can change.
Typical examples include:
- delivery required earlier;
- delivery required later;
- quantity increased;
- quantity reduced;
- order cancelled;
- delivery split;
- supplier proposes a new delivery date;
- supplier can only deliver part of the quantity;
- supplier reports a capacity or material constraint.
If these changes are not managed properly, procurement can end up with an order book that no longer reflects reality.
That can contribute to:
- material shortages;
- unnecessary inventory;
- excess and obsolete material;
- expediting;
- production disruption;
- incorrect supplier priorities;
- poor cash and working-capital decisions;
- disagreement about the current commitment.
The operative buyer’s role is therefore to keep the open order book aligned with the latest controlled position.
Where Active PO Management fits in the purchasing process
A simplified operational purchasing sequence looks like this:
PO transmitted
↓
Supplier acknowledgement
↓
Initial order confirmed
↓
Requirement or supplier situation changes
↓
PO change identified
↓
Change communicated and supplier response managed
↓
Latest agreed position recorded
↓
Open order continues toward delivery
Active PO Management starts when an already-issued or confirmed order needs to change.
This is different from initial Order Acknowledgement.
Order Acknowledgement asks:
Did the supplier confirm the original order?
Active PO Management asks:
What happens when that confirmed order later needs to change?
What counts as a Purchase Order change?
A PO change can originate from either the buying organization or the supplier.
Buyer-requested changes
Typical examples include:
- Pull-in: delivery required earlier
- Push-out: delivery required later
- Quantity increase
- Quantity decrease
- Cancellation
- Delivery split
- Rescheduling of a range of delivery positions.
- Change of delivery location where commercially and operationally permitted
Supplier-proposed changes
The supplier may also initiate a change.
Examples include:
- delivery delay;
- partial delivery;
- quantity restriction;
- capacity problem;
- raw-material shortage;
- transportation problem;
- production interruption.
The reason for the change may be external.
But the operative buyer still needs to bring the order back into a controlled state.
That is why both buyer-triggered and supplier-triggered changes belong in Active PO Management.
Requested requirement and supplier-confirmed commitment are not the same thing
This is one of the most important principles in open-order management.
Assume the supplier has confirmed:
500 units on 30 June
Planning then asks procurement to change the requirement to:
500 units on 15 June
The new date is a requested date.
It is not yet the supplier’s confirmed commitment.
Until the supplier accepts the change, the buyer should keep the distinction clear:
Requested date: What the buying organization currently wants.
Confirmed date: What the supplier has committed to.
If the supplier replies:
Earliest possible delivery: 24 June
procurement now has three pieces of information:
- old confirmed date: 30 June;
- requested new date: 15 June;
- supplier-proposed date: 24 June.
The operative buyer must manage the difference.
Simply replacing the confirmed date with 15 June before the supplier agrees can make the order book unreliable.
The principle is:
Never confuse a requested PO change with an agreed PO change. Maintain visibility of both requirement and commitment until the difference is resolved.
KPI definition: PO Change Control Rate
Purpose
Ensure Purchase Order changes are identified, communicated, resolved or escalated, and correctly reflected in the purchasing system.
Primary owner
Operative Buyer
Supporting interfaces
- Planning
- Supplier
- Production
- Logistics
- Tactical Procurement
- Inventory Management
Scope
Eligible changes to open Purchase Orders, lines or delivery schedules.
Start point
A valid PO change event is received or identified.
End point
The change is in a controlled status and the purchasing system reflects the latest agreed position, or an unresolved exception has been formally escalated.
Measurement frequency
Operationally daily or weekly.
KPI reporting may be monthly.
Formula
PO Change Control Rate (%) = Eligible PO change events correctly processed or brought under control within SLA ÷ Total eligible PO change events due for control × 100
The four-step Active PO Management process
A practical PO change process can be structured into four steps.
Step 1 – Change identified
A valid change requirement appears.
This may come from:
- Planning
- Production
- Customer demand
- Inventory review
- Supplier
- Quality
- Logistics
The operative buyer should first understand:
- What changed?
- Why?
- Which PO line or schedule is affected?
- How urgent is the change?
- Is the request commercially and operationally valid?
Not every message should immediately become a PO amendment.
The change first needs to be understood.
Step 2 – Change assessed and communicated
The buyer evaluates the change against available information such as:
- current confirmed date;
- current confirmed quantity;
- supplier lead time;
- contractual flexibility;
- frozen period;
- cancellation conditions;
- minimum quantities;
- inventory position.
The valid request is then communicated to the supplier through the agreed process.
Step 3 – Supplier response managed
The supplier may:
- accept the change;
- partially accept;
- propose an alternative;
- reject;
- fail to respond.
The operative buyer needs to understand the response and determine what happens next.
Step 4 – System and planning records aligned
Once the outcome is agreed, the Purchase Order and relevant planning records should reflect the latest controlled position.
If the change remains unresolved, the exception should be visible and escalated.
The process is not complete simply because an email was sent.
It is complete when the organization knows the current requirement, the supplier’s commitment and the action required.
Not every requested change can be achieved
A good KPI should not encourage unrealistic behavior.
Suppose Planning requests a pull-in from:
30 June → 15 June
The operative buyer contacts the supplier immediately.
The supplier responds:
15 June is impossible. Earliest possible delivery is 24 June.
The buyer discusses the issue with Planning and escalates the remaining gap.
The requested change was not fully achieved.
But the operative buyer has controlled the process correctly.
This is why the internal KPI should measure change control, not simply supplier acceptance.
A valid pull-in should always be evaluated and actioned promptly.
That does not mean every requested date can be achieved.
Supporting KPI: Change Communication Lead Time
The buyer’s speed can be measured separately.
Buyer Change Communication Lead Time
Buyer Change Communication Lead Time = Change becomes actionable → Change transmitted to supplier
This measures how quickly procurement acts once a valid requirement changes.
For example:
Planning approves a pull-in at 09:00.
The buyer communicates it to the supplier at 11:00.
Change Communication Lead Time = 2 hours
This is primarily an internal execution measure.
Supporting supplier KPI: Change Response Lead Time
The supplier’s responsiveness should be measured separately.
Supplier Change Response Lead Time
Supplier Change Response Lead Time = Change transmitted → Supplier response received
This measures how quickly the supplier responds to the buyer’s change request.
A supporting supplier KPI can also be:
Supplier Change Response On-Time Rate
Supplier Change Response On-Time Rate (%) = Change requests answered within agreed response time ÷ Total change requests due × 100
This belongs to supplier-performance management rather than the operative buyer’s internal KPI.
Read more:
Supplier Performance KPIs – Supporting the Operative Buyer’s KPIs
Supporting supplier KPI: Supplier Change Acceptance Rate
Supplier flexibility can also be measured.
Supplier Change Acceptance Rate
Supplier Change Acceptance Rate (%) = Valid buyer-requested changes accepted by supplier ÷ Total valid buyer-requested changes × 100
This may be useful in categories where flexibility is commercially important.
For example:
A supplier that can frequently support:
- pull-ins;
- push-outs;
- quantity adjustments;
- cancellations;
may provide greater operational flexibility than a supplier with very rigid production constraints.
But this should not be confused with internal buyer performance.
A low supplier acceptance rate does not automatically mean the operative buyer performed poorly.
It may indicate:
- inflexible capacity;
- long material lead times;
- contractual limitations;
- frozen production periods;
- supplier constraints.
Use different SLAs for different change priorities
Not every PO change has the same urgency.
A pull-in needed to prevent a production stop is very different from a push-out requested six months before delivery.
A practical model can classify changes, for example:
Critical change
Immediate or near-term risk to:
- production;
- customer delivery;
- safety;
- critical service.
Required buyer action may be measured in hours.
Standard operational change
A normal adjustment within the planning horizon.
Required action may be measured within an agreed working-day SLA.
Administrative change
A change with little immediate supply impact.
A longer SLA may be appropriate.
The KPI can still aggregate the different change types by measuring whether each change was controlled within its applicable SLA.
Understand the agreed flexibility before requesting a change
Not every Purchase Order can be changed freely.
The operative buyer should understand the commercial and operational flexibility agreed with the supplier.
Relevant conditions may include:
- frozen periods;
- rescheduling windows;
- permitted quantity variation;
- cancellation notice;
- liability for committed materials;
- minimum order quantities;
- capacity commitments;
- flexibility bands;
- production lock periods.
For example:
A contract might allow:
±20% quantity change outside eight weeks
but only:
±5% inside four weeks
and:
no cancellation inside two weeks without cost
The exact structure depends on the category and agreement.
The important principle is:
Active PO Management starts with understanding the flexibility that was agreed before the change occurs.
The operative buyer should not promise that a requirement can be changed before understanding the supplier and contractual consequences.
Develop this topic further with:
Operative Procurement Processes 3
Measure PO Change Rate as a diagnostic
The number of Purchase Order changes can provide useful information about operational stability.
But the absolute number can be misleading.
A buyer managing 10,000 PO schedules will naturally experience more changes than a buyer managing 500.
A normalized measure can therefore be useful.
PO Change Rate
PO Change Rate (%) = Number of PO change events ÷ Relevant open PO schedules × 100
Another option is:
Number of changes per 100 open PO schedules
The purpose is trend analysis.
A rising change rate might indicate:
- demand volatility;
- production-plan changes;
- inaccurate planning assumptions;
- customer changes;
- inventory adjustments;
- supplier instability.
But a high change rate should not automatically be labelled poor buyer performance.
It is a diagnostic.
It tells procurement:
Something in the operating environment is creating more change. Investigate why.
Use reason codes for PO changes
Reason codes make the KPI much more useful.
Possible reasons include:
Buyer-side or demand-related
- Customer demand change
- Production rescheduling
- Forecast revision
- Inventory reduction
- E&O avoidance
- Project change
- Original PO error
Supplier-related
- Capacity constraint
- Material shortage
- Quality issue
- Production interruption
- Transportation problem
Process or system-related
- Master-data error
- Planning-system error
- Incorrect lead time
- Duplicate demand
Consider the difference between these two statements:
“We processed 500 PO changes last month.”
and:
“42% of our push-outs were caused by production-plan changes, while 18% resulted from supplier capacity issues.”
The second statement provides management information.
A practical Active PO Management KPI example
Assume 50 PO change events occur during a month.
They include:
- 20 pull-ins;
- 12 push-outs;
- 8 quantity changes;
- 4 cancellations;
- 6 supplier-proposed delivery changes.
By the applicable internal control SLA:
- 46 are resolved or correctly escalated;
- 4 remain without appropriate action.
The internal KPI is:
PO Change Control Rate = 46 ÷ 50 × 100 = 92%
Now look at the buyer-requested changes.
There were 44.
The suppliers:
- accepted 29 exactly as requested;
- proposed alternatives for 10;
- rejected 5.
The operative buyer KPI should not be:
29 ÷ 44 = 66%
because that would measure supplier flexibility more than buyer control.
Instead:
Internal buyer question
Were all 44 buyer-requested changes controlled correctly?
Supplier question
How frequently could suppliers accommodate the requested changes?
Those are different measures.
Monitor the Open PO Change Backlog
A useful operational diagnostic is:
Open PO Change Backlog
This is the population of change events that have not yet reached a controlled state.
Ageing can be grouped into:
- 0–1 working day
- 2–3 working days
- 4–7 working days
- More than 7 working days
A practical worklist might show:
| Supplier | PO | Change | Required date | Age | Criticality | Status |
|---|---|---|---|---|---|---|
| Supplier A | 450123 | Pull-in | 15 May | 1 day | High | Supplier reviewing |
| Supplier B | 450456 | Quantity reduction | 30 June | 3 days | Medium | Buyer follow-up |
| Supplier C | 450789 | Cancellation | 15 July | 8 days | High | Commercial escalation |
This helps the operative buyer prioritize the changes that create the greatest operational risk.
Do not let the percentage hide critical changes
Suppose:
PO Change Control Rate = 98%
That appears strong.
But the missing 2% could contain:
- one urgent production pull-in;
- one cancellation intended to prevent expensive obsolete material.
The KPI percentage measures overall discipline.
The exception list manages operational risk.
Both are required.
A good operative buyer does not allow a high percentage to hide a critical unresolved transaction.
PO changes and working capital
Active PO management can influence inventory and working capital.
Examples include:
Push-out
If demand has moved later, delaying delivery may prevent material arriving unnecessarily early.
Quantity reduction
If expected demand declines, reducing an open quantity may prevent excess inventory.
Cancellation
If demand disappears, cancelling an order before the supplier has committed too much cost may reduce obsolete-material exposure.
Pull-in
If demand increases unexpectedly, earlier delivery may protect production or customer delivery.
These are important business effects.
But the Active PO Management KPI should not attempt to measure them directly.
The KPI measures:
Did procurement control the change?
Working-capital and inventory outcomes should be evaluated separately.
PO changes and Excess & Obsolete material
PO change management has a particularly important connection to excess and obsolete inventory.
Imagine demand for a component falls sharply.
There are still several open Purchase Orders due over the coming months.
The operative buyer may need to:
- reduce quantities;
- push out deliveries;
- cancel orders;
- negotiate liability for supplier-held material.
If procurement does not act quickly, material may continue to arrive even though demand has disappeared.
Good Active PO Management therefore supports E&O prevention.
But E&O remains its own operational control area.
Read more:
KPI Excess & Obsolete Material Management
Active PO Management and Order Acknowledgement
Initial Order Acknowledgement creates the first confirmed supplier position.
For example:
Ordered: 1,000 units on 30 June
Supplier confirmed: 1,000 units on 30 June
The order is aligned.
Later, Planning changes the requirement:
New requested date: 15 June
The operative buyer now enters Active PO Management.
The supplier may respond:
Confirmed revised date: 20 June
That becomes the latest agreed commitment.
The sequence is:
Original PO
↓
Supplier acknowledgement
↓
Initial confirmed commitment
↓
Requirement changes
↓
PO change request
↓
Supplier response
↓
Latest confirmed commitment
This is why current confirmation data matters so much.
Read more about the initial control point:
Order Acknowledgement KPI for Operative Buyers
Active PO Management versus Overdue PO Control
These are related but different processes.
Active PO Management
Focuses on changes to an open order before or during its lifecycle.
The question is:
When circumstances change, do we keep the order aligned?
Overdue PO Control
Focuses on open orders where the valid confirmed delivery date has passed and the line remains unresolved.
The question becomes:
Has part of the open order book become past due or stale?
Keeping the two KPIs separate helps identify different process problems.
Active PO Management is about change control.
Overdue PO Control is about order-book hygiene and late commitments.
Continue to the next KPI here:
Overdue Purchase Order KPI for Operative Buyers
Data sources for Active PO Management
Typical data sources include:
- ERP
- MRP
- Procurement platform
- Planning system
- Supplier portal
- EDI
- Structured supplier communication
Useful fields may include:
- PO number
- PO line
- Delivery schedule
- Supplier
- Previous requested date
- Previous confirmed date
- New requested date
- New confirmed date
- Previous quantity
- Requested quantity
- Confirmed quantity
- Change type
- Change source
- Reason code
- Change-request timestamp
- Supplier-response timestamp
- Buyer action timestamp
- Change status
The objective is to maintain a traceable view of:
what changed, why it changed, when it changed and what was finally agreed.
Automating PO change management
At low maturity, buyers may manage changes manually through:
- email;
- spreadsheets;
- ERP updates;
- phone calls.
That can work at low transaction volumes.
At higher volumes, structured workflows become increasingly valuable.
Potential automation can include:
- automatic change messages;
- supplier portals;
- EDI;
- workflow alerts;
- automatic date comparison;
- automatic quantity comparison;
- exception alerts;
- electronic supplier confirmations.
The objective should not be to automate professional judgment.
It should be to automate predictable transactions so the operative buyer can focus on exceptions.
Eligible Electronic PO Change Rate
A possible higher-maturity measure is:
Eligible Electronic PO Change Rate
Eligible Electronic PO Change Rate (%) = Eligible PO changes processed through structured electronic workflow ÷ Total PO changes eligible for electronic processing × 100
Again, use the word eligible.
Some transactions may require commercial or operational discussion.
Automation should focus on standardized changes within agreed rules and tolerances.
Active PO Management maturity
The LHTS learning level for this article is Basic.
KPI maturity describes how the process develops.
Maturity stage 1 – Change discipline
Procurement can answer:
- Which PO changes exist?
- Who requested them?
- Were they communicated?
- Did the supplier respond?
- Was the result updated?
The focus is visibility.
Maturity stage 2 – Exception and ageing control
Procurement also measures:
- PO Change Control Rate
- Change backlog
- Backlog ageing
- Change type
- Reason code
- Buyer response time
- Supplier response time
The focus becomes root cause and prioritization.
Maturity stage 3 – Planning integration
PO changes are systematically connected with planning and purchasing workflows.
The organization maintains clear visibility of:
- current requirement;
- current confirmed supplier commitment;
- unresolved gaps.
The order book becomes more reliable.
Maturity stage 4 – Exception-based automation
Routine changes within agreed commercial and operational tolerances can flow electronically.
For example:
Approved planning change → supplier change message → supplier response → system update
Clean transactions require little manual buyer effort.
The operative buyer focuses on:
- rejected changes;
- critical pull-ins;
- supplier capacity constraints;
- commercial consequences;
- high-risk exceptions.
The principle is:
Automate predictable changes. Apply buyer judgment to exceptions.
Desired behaviour created by the KPI
A well-designed Active PO Management KPI should encourage the operative buyer to:
- Monitor changes to open requirements
- Act quickly when a valid change is received
- Understand contractual flexibility
- Keep requested and confirmed dates separate
- Communicate changes through the agreed process
- Follow up supplier responses
- Resolve or escalate differences
- Update ERP data correctly
- Maintain a reliable open order book
- Identify recurring causes of change
- Reduce unnecessary inventory exposure
- Focus on operationally critical exceptions
The objective is not simply to process more change messages.
The objective is to keep the purchasing commitment aligned with reality.
Common Active PO Management KPI mistakes
Measuring supplier acceptance as buyer performance
The buyer controls the change process.
The supplier controls whether it can accept the requested change.
Measure these separately.
Replacing the confirmed date with the requested date before supplier agreement
This destroys visibility of the supplier’s real commitment.
Maintain both requirement and confirmation until resolution.
Treating every pull-in as achievable
Every valid pull-in should be actioned promptly.
That does not mean the supplier can always support it.
Counting only buyer-requested changes
Supplier-proposed changes also require active PO control.
Measuring only total change volume
Normalize the volume and use reason codes.
The number alone provides limited insight.
Treating all changes as equally urgent
Use appropriate SLAs based on operational impact.
Ignoring contractual flexibility
Understand frozen periods, cancellation rules and rescheduling conditions before promising a change.
Sending a change but failing to update the system
A successful supplier discussion has little value if ERP still contains obsolete information.
Allowing unresolved changes to remain invisible
Use a PO Change Backlog with ageing.
Blaming Planning for every PO change
High change volume is a diagnostic.
Investigate the cause rather than assuming it represents poor upstream performance.
Mixing change control with overdue-order management
Active PO Management controls changes.
Overdue PO Control manages past-due commitments.
Keep the KPIs separate.
A practical monthly Active PO Management dashboard
A Basic-level dashboard might contain:
| Measure | Result | Target |
|---|---|---|
| PO Change Control Rate | 92% | ≥95% |
| Median Buyer Change Communication Lead Time | 3.1 hours | ≤4 hours |
| Open PO Change Backlog | 7 | 0 critical |
| >7-day unresolved changes | 2 | 0 |
| PO Change Rate | 8.4 per 100 schedules | Trend |
| Supplier Change Response On-Time Rate | 91% | ≥95% |
| Supplier Change Acceptance Rate | 68% | Monitor |
The dashboard should then lead to questions:
Why are changes not being controlled within SLA?
Which unresolved change carries the highest business risk?
Why is PO Change Rate increasing?
Which suppliers respond slowly?
Why are suppliers rejecting pull-ins?
Are planning changes occurring inside agreed frozen periods?
Those questions create improvement.
The dashboard itself does not.
Develop your knowledge with Operative Procurement Processes 3
Active PO Management is part of a broader set of operational purchasing activities.
The LHTS Operative Procurement Processes 3 course provides the knowledge foundation for this article.
It connects:
- Forecast and Purchase Order requirements
- Order acknowledgement
- Order management
- Discrepancies
- Excess and obsolete material
- Supply-chain flexibility
Take Operative Procurement Processes 3 at Learn How to Source
For supplier-side responsiveness and flexibility measures, continue with:
Supplier Performance KPIs – Supporting the Operative Buyer’s KPIs
Frequently asked questions about Active PO Management KPIs
What is Active PO Management?
Active PO Management is the process of controlling changes to open Purchase Orders after they have been issued or confirmed.
It includes changes to dates, quantities, schedules and cancellations, as well as supplier-proposed changes.
What is the PO Change Control Rate?
PO Change Control Rate measures the proportion of eligible PO change events that are correctly processed or brought under control within the defined SLA.
Does the supplier need to accept the change for the KPI to succeed?
No.
The operative buyer is responsible for controlling the process.
If the supplier rejects a valid change request and the buyer correctly resolves or escalates the issue, the process can still be considered under control.
What is the difference between requested date and confirmed date?
The requested date is what the buying organization wants.
The confirmed date is what the supplier has committed to.
They should remain separate until the supplier accepts the requested change.
What is a pull-in?
A pull-in is a request to move delivery earlier.
For example:
Confirmed date: 30 June
New requested date: 15 June
What is a push-out?
A push-out is a request to move delivery later.
This can help avoid early inventory when demand has moved.
Should every PO change be accepted by the supplier?
No.
The supplier may have capacity, material, contractual or production constraints.
The buyer’s responsibility is to manage the resulting difference.
What is PO Change Rate?
PO Change Rate measures how frequently changes occur relative to the relevant open-order population.
It is mainly a diagnostic of operational volatility.
Is a high PO Change Rate always bad?
No.
It can reflect legitimate demand changes or an inherently volatile business environment.
The important question is why the changes occur and whether they are controlled effectively.
Should supplier-requested changes be included?
Yes.
Supplier-requested changes still require the operative buyer to assess, communicate, resolve and update the latest position.
The cause can be classified separately as supplier-related.
What is an Open PO Change Backlog?
It is the population of PO change events that have not yet reached a controlled state.
Ageing and criticality help buyers prioritize the most important exceptions.
How is Active PO Management different from Overdue PO Control?
Active PO Management controls changes to open orders.
Overdue PO Control identifies orders where the valid confirmed date has passed and the transaction remains unresolved.
Can PO change management be automated?
Yes.
At higher maturity, routine changes can be exchanged through electronic workflows, EDI or supplier platforms.
The operative buyer can then focus mainly on exceptions.
Conclusion: Keep the order aligned with reality
A confirmed Purchase Order is only useful if it continues to reflect the current operational reality.
Demand will change.
Suppliers will face constraints.
Dates will move.
Quantities will change.
The operative buyer’s responsibility is not to prevent all change.
It is to control change.
The recommended headline KPI is:
PO Change Control Rate (%) = Eligible PO change events correctly processed or brought under control within SLA ÷ Total eligible PO change events due for control × 100
Support it with:
Buyer Change Communication Lead Time
to measure how quickly procurement acts.
Open PO Change Backlog & Ageing
to identify unresolved exposure.
PO Change Rate
to understand operational volatility.
Supplier Change Response On-Time Rate
to measure supplier responsiveness.
Supplier Change Acceptance Rate
to understand supplier flexibility.
The most important operating principle is:
Requested requirement and supplier-confirmed commitment are not the same thing.
When something changes:
Identify it.
Validate it.
Communicate it.
Get the supplier response.
Resolve the difference.
Update the system.
That keeps the open order book reliable and gives Planning, Procurement and the supplier a common understanding of the latest position.
Your next step
Review recent changes to your open Purchase Orders.
Ask:
- How many pull-ins occurred?
- How many push-outs?
- How many quantity changes or cancellations?
- Which changes originated with suppliers?
- Were changes communicated promptly?
- Did suppliers respond?
- Are requested and confirmed dates kept separate?
- Which changes remain unresolved?
- Why are changes occurring?
- Does ERP reflect the latest agreed commitment?
Then ask the next operational-control question:
What happens when the confirmed delivery date passes and the Purchase Order is still open?
That leads to the next KPI in the LHTS Operative Buyer KPI system: