Quick answer
If your Freight Units look correct but still won’t combine, check in this order:
- Were they even selected into the same planning run? If not, nothing else matters.
- Can one vehicle realistically serve both, given the time constraints?
- Is an incompatibility setting keeping them apart?
- Has a capacity limit been reached?
- What do the planning profile and strategy actually allow?
And one more: if nothing is blocking the combination, the optimizer may simply have chosen a different arrangement. That is a different problem.
Most people start at step 2. Start at step 1 instead — it saves hours.
The problem
The Freight Units are fine. You have checked them.
Same customer. Same destination. Same day. Both small enough to fit on one truck. Everything looks the way it should.
Then you run planning, and SAP TM gives you two Freight Orders.
Nobody can see why. So someone opens the Freight Unit Building Rule and starts changing things — and usually makes it worse, because the rule was never the problem.
Here is the thing that catches most teams out: a correct Freight Unit does not mean a consolidated Freight Order. They are two different steps, and the second one has its own set of rules.
If the Freight Units are correct but the expected consolidation does not happen, look at transportation planning before you touch Freight Unit Building — the scheduling, the constraints, the network and resource data, and the optimizer’s behaviour.
This article walks through the five main areas to check first, followed by several other causes worth ruling out.
If you want the full picture — how deliveries, Freight Unit Building and planning all fit together — start with our main article on [why SAP TM creates too many Freight Orders].
How Freight Unit consolidation works
Short version:
Delivery → Freight Unit Building → Freight Units → Transportation Planning → Freight Orders
The delivery arrives. Freight Unit Building turns it into one or more Freight Units. Those Freight Units are the transportation requirements SAP TM uses as the basis for planning.
During transportation planning, SAP TM evaluates whether Freight Units can be planned together, based on constraints, resources, schedules, network data and the configured planning strategy.
That evaluation is where consolidation is decided.
Why SAP TM does not consolidate Freight Units
SAP TM combines Freight Units when the planning constraints allow it and the resulting plan fits the objective it has been given.
A single constraint is enough to prevent it. It does not matter how similar the two Freight Units look to you. And even where nothing blocks the combination, the optimizer may still produce a different arrangement.
So the job is not to make the Freight Units “more similar.” The job is to find out what is actually driving the result.
Two different reasons, often confused
Before working through the causes, it helps to separate two things that look identical from the outside.
Reason one: something is blocking it. A constraint makes the combination impossible. A window can’t be met, an incompatibility applies, a capacity limit is reached. Planning could not have produced the plan you wanted.
Reason two: nothing is blocking it — the optimizer just chose differently. The combination was possible. The optimizer evaluated it against the costs, the routes, the schedules and the objective it was given, and decided another arrangement scored better.
These need different responses. The first is a constraint to find. The second is a question about what your planning is optimising for, and whether that matches what the business actually wants.
If you have checked every constraint and none of them explains the result, you are probably looking at the second case.
Can two Freight Units fit on one truck and still not be combined? Yes. If nothing blocks the combination, the optimizer may still produce a different arrangement because it scored better against the objective, costs and routes it was given. Feasible is not the same as preferred — and that difference needs a different conversation, about what your planning is optimising for.
1. The Freight Units were never in the same planning run
Start here. Always.
Two Freight Units cannot be combined if the system never looked at them together. And this is far more common than people expect.
Why it stops consolidation: planning only works with what it is given. The selection settings decide which Freight Units enter the run. If your two Freight Units went into two different runs, they never had a chance to meet.
Business impact: two Freight Orders that should have been one. And nothing in the system flags it, because nothing failed.
How to spot it: open the planning run and check whether both Freight Units are actually in the list. If only one is there, stop — you have found it.
Where to check: the selection profile and selection settings in your planning profile. Also check the planning horizon and the date ranges. And check whether background runs and manual runs use different selections.
Usual fix: widen the selection, adjust the horizon, or change when the run happens so both Freight Units are ready in time.
2. The time constraints can’t be met on one tour
Why it stops consolidation: every Freight Unit carries pickup and delivery time constraints. Two stops don’t need identical windows — a vehicle can serve one customer at 10:00 and another at 14:00. What matters is whether all the required activities can be scheduled on one feasible tour, including travel, loading and unloading time.
If they cannot be satisfied together within a feasible tour, the planning result may require the Freight Units to remain in separate Freight Orders.
The catch is where these constraints come from. Depending on your scheduling setup and configuration, they can be influenced by requested delivery dates, other document dates, and transportation scheduling. In many systems they end up tighter than what the customer actually needs — which is worth checking before you assume the dates are fixed.
Business impact: a frequent cause of half-empty trucks. Two loads that could have travelled together, sent separately, because of a few hours on paper.
How to spot it: open both Freight Units and put the time constraints side by side, then ask whether one vehicle could realistically serve both — including the travel time between them.
Where to check: the date and time fields on the Freight Units, and the scheduling and planning settings that determine how time constraints are evaluated in your system.
Usual fix: first, agree with the business what “can travel together” really means. Then adjust the relevant settings to match. Do not skip the first part — without it you are just guessing.
3. An incompatibility setting is keeping them apart
Why it stops consolidation: incompatibilities are rules that say certain things should not share a vehicle. They are meant to protect you. Depending on the type and how it is set up, an active incompatibility can stop planning from combining two Freight Units regardless of how much sense the combination would otherwise make.
Common examples:
- Hazardous goods that cannot travel with certain other products
- Frozen and ambient goods on the same vehicle
- Customers who have asked not to be combined with others
- Products that don’t suit a particular vehicle type
Business impact: consolidation that quietly never happens, often for a rule someone set years ago and nobody has reviewed since.
How to spot it: check whether the two Freight Units share any attribute covered by an incompatibility — product group, dangerous goods class, customer, temperature requirement.
Where to check: your incompatibility definitions and settings, and whether the planning profile is applying them.
Common mistake: setting an incompatibility too widely. A rule meant for one product group ends up blocking a whole category.
4. A capacity limit has been reached
Why it stops consolidation: a vehicle has limits — weight, volume, pallet spaces, loading metres. If the combined demand can’t be accommodated by the available resource under the applicable capacity constraints, the planning strategy may require separate Freight Orders.
Business impact: if the limit is real, this is correct behaviour. If it is wrong, you are paying for trucks you don’t need.
How to spot it: add up the weight and volume of both Freight Units and compare with the vehicle limits. If they fit comfortably, capacity is not your problem — move on.
Where to check: the means of transport and vehicle resource settings, and the capacity data on the Freight Units themselves.
Common mistake: the numbers are wrong, not the settings. Product weights and dimensions come from master data. If they are missing, out of date, or entered in the wrong unit, planning is working with bad figures. This is worth checking before you touch any configuration.
5. SAP TM planning profile or strategy isn’t aligned with the business requirement
Why it stops consolidation: the planning profile determines much of what the run does — which Freight Units are selected, which planning strategy applies, and how the optimizer behaves.
But it does not control everything. Master data, network data, incompatibility configuration, resource constraints and scheduling data can all affect the result independently. That distinction matters, because it decides where you look next.
This is where a system can appear correct everywhere else and still produce a plan nobody wanted.
Business impact: consolidation never improves, however much time is spent on Freight Unit Building. The resulting behaviour is being shaped by the planning profile, the planning strategy, or another planning input.
How to spot it: if you have checked the four causes above and found nothing, look here — and at whether the objective the optimizer is pursuing matches what the business considers a good plan.
Where to check:
- Selection settings — which Freight Units come in
- The planning strategy in use
- Optimizer runtime and termination settings — a shorter runtime may return a feasible solution before a better one is found
- How capacity and incompatibilities are applied during planning
- The scheduling settings that govern time constraints
Usual fix: decide what the business actually wants first, then align the profile and strategy to match. Changing settings one at a time to see what happens tends to move the problem rather than solve it.
A real example
Two deliveries. Same customer, same city, same day. Both Freight Units built correctly. Both easily fitting on one truck.
Planning still produced two Freight Orders.
The Freight Unit Building Rule was checked first, and found to be fine. The block turned out to be the time constraints — they sat about four hours apart, derived from the requested delivery dates. The planning configuration allowed only around two hours of flexibility around those constraints.
So the two Freight Units were, on paper, incompatible by a couple of hours.
The fix was not technical to begin with. The business agreed that the two shipments could travel together if the relevant time constraints could be accommodated within a three-hour flexibility. That was a business rule, not an SAP parameter. The relevant planning and scheduling settings were then adjusted to support it.
No change was made to SD or to Freight Unit Building. Neither was ever the problem.
Diagnostic checklist
Work down this list in order. Stop when you find the block.
| Check | Why it matters | Where to verify |
|---|---|---|
| Are both Freight Units in the same planning run? | If not, nothing else applies | Planning run list, selection profile |
| Does the planning horizon cover both? | A Freight Unit outside the horizon is invisible | Planning profile, date settings |
| Were both Freight Units ready at run time? | Late arrival means it missed the run | Freight Unit creation timestamps |
| Can one vehicle realistically serve both stops? | Windows need not overlap — the tour must be feasible | Freight Unit date fields, travel times |
| How much flexibility do the time constraints allow? | Often tighter than the business needs | Scheduling and planning settings |
| Is any incompatibility active for these two? | One rule is enough to block | Incompatibility settings |
| Is the incompatibility set too widely? | A narrow rule applied broadly | Incompatibility definitions |
| Does the combined weight fit? | Real limit vs wrong data | Means of transport, master data |
| Does the combined volume fit? | Same | Means of transport, master data |
| Are product weights and dimensions correct? | Bad data produces correct-looking wrong plans | Product master |
| Is there a suitable transportation lane for the combined route? | An unsuitable lane can block the intended plan | Transportation lane and network setup |
| Is the optimizer runtime long enough? | A short runtime may stop at a feasible, not better, solution | Planning profile |
| Does the optimizer’s objective match what the business wants? | A feasible combination can still lose to a cheaper alternative | Planning strategy and cost settings |
Other causes worth ruling out
These come up less often, but they do come up.
Missing or unsuitable transportation lanes. A missing or unsuitable lane, or a network option that doesn’t fit the combined route, can prevent planning from building the plan you expected.
Freight Unit attributes that don’t match. Different shipping conditions, modes of transport, carrier requirements or equipment needs will keep two Freight Units apart even when everything else lines up.
Master data gaps. Product dimensions, weights, packaging data, location master and resource master all feed planning. When they are wrong, planning behaves oddly in ways that look like configuration problems but aren’t.
Each of these deserves its own proper look. We’ll cover them separately.
When the problem is not configuration
Sometimes you check everything, and every setting is technically correct — and the plan is still wrong.
That usually points to something further back:
- A transportation design that no longer matches how the business distributes
- Business rules that were never written down clearly
- Old customisation that still runs and nobody remembers
- Master data that has drifted over the years
- Decisions taken during implementation for reasons that no longer apply
There is one point worth stating plainly, because it decides everything else:
You cannot configure consolidation until the business has decided what “should travel together” actually means.
If that rule cannot be written in one sentence, no setting will produce it reliably. You will keep adjusting the system and keep getting results that feel almost right.
That is a business decision, not an SAP one — and it usually has to happen before any configuration work makes sense.
How SCM Champs helps
When Freight Units are correct and still won’t combine, the answer is somewhere in planning — and finding it takes a structured pass rather than trial and error.
We help teams work through:
- Selection settings and planning horizons — the check most people skip
- Planning profiles, scheduling settings and consolidation behaviour
- Incompatibilities that block more than they were meant to
- Capacity limits, and whether the master data behind them is right
- Whether the optimizer’s objective matches what the business calls a good plan
- Whether the business rule behind consolidation has ever been agreed
The aim is to find what is actually driving the result, understand why, and change only that.
Frequently asked questions
Why are Freight Units not consolidating even though they have the same destination? Same destination is not enough. Time constraints, incompatibilities, capacity and the planning strategy all have to allow it, and the optimizer has to prefer that arrangement. Check whether the two Freight Units were even in the same planning run first.
How do I know if my Freight Units were included in the same planning run? Open the run and look at the list. If only one of the two appears, the selection settings or planning horizon are the cause, and nothing else needs checking.
Can capacity limits stop Freight Unit consolidation? Yes. If the combined demand exceeds what the available resource can carry under the applicable constraints, separate Freight Orders may be required. Check whether the limit is real or the product master data is wrong.
Does the SD delivery split affect Freight Unit consolidation? An SD delivery split determines which delivery documents reach downstream processing, so it influences which Freight Units are available for planning. But once the relevant Freight Units have been created correctly, whether they are planned together depends on transportation planning, scheduling, constraints, network and resource data, and the planning strategy in use.
Can incompatibility settings override planning rules? They can. Depending on the type and setup, an active incompatibility can stop planning from combining two Freight Units, however sensible the combination would otherwise be.
Which planning profile settings control consolidation? Selection settings, the planning strategy, optimizer settings, and how capacity and incompatibilities are applied during planning. Note that scheduling data, network data and master data can affect the result independently of the profile.
Can two Freight Units fit on one truck and still not be combined? Yes. If nothing blocks the combination, the optimizer may still produce a different arrangement because it scored better against the objective, costs and routes it was given. Feasible is not the same as preferred.
How do transportation lanes affect planning? A missing or unsuitable lane for the combined route can prevent planning from building that Freight Order, even when every other constraint allows it.
Can incorrect master data prevent consolidation? Yes, and it is easy to miss. Wrong product weights or dimensions make planning think a vehicle is full when it isn’t. Check the numbers before changing settings.
In short
Getting Freight Units to consolidate takes more than running the planning engine.
It needs the right Freight Units in the same run, constraints that can be satisfied together, accurate master data, and a planning profile and strategy that reflect what the business actually wants.
When consolidation isn’t happening, the goal is to find what is actually driving the result — not to change several settings and hope. Work down the list in order, starting with selection. And if every constraint checks out, the question shifts: it may not be a block at all, but a plan the optimizer preferred for reasons worth understanding.
For the wider picture of how deliveries, Freight Unit Building and planning fit together, see [why SAP TM creates too many Freight Orders].
Not sure why your plan isn’t consolidating?
SCM Champs can review your planning setup end to end, identify the underlying cause, and show you what needs to change.
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