Planning Production on Lines
Production Items define what will be produced.
Production Lines define where and when it will be produced.
Planning production means assigning Production Items to Production Lines and arranging them into a feasible production sequence.
This is the step where production changes from a list of items into an actual production plan.
This page explains:
how production planning works in P4,
how Production Items are assigned to Production Lines,
what “planned” really means in practice.
What is a Production Line?
A Production Line represents a real or logical manufacturing resource.
In P4, a Production Line:
has its own capacity and working time,
can process specific materials,
executes Production Items (usually) one by one in a defined order.
Production Lines are usually:
machines,
assembly lines,
work centers,
or logical groupings of capacity.
Production Lines provide capacity.
Production Items consume that capacity.
Where production planning happens
Production planning is done in Parallel Planning (Production Control - Resources - Production Lines).
Parallel Planning shows:
all Production Lines,
all unassigned Production Items,
the current production queues on each line.
At a glance, you can see:
what is planned,
what is waiting,
and what still needs attention.
This is the main workspace for production planners.
Assigning Production Items to Production Lines
To plan production, Production Items must be assigned to a Production Line.
There are two basic ways to do this:
manual assignment,
automatic assignment (if available in your setup).
In both cases, the result is the same:
the Production Item is placed into the queue of a specific Production Line,
its planned start and finish times are calculated.
Once assigned, the Production Item becomes part of the production plan.
Understanding unassigned Production Items
Production Items that are not assigned to any line are shown as unassigned.
This usually means:
planning has not been done yet,
or the item cannot be planned automatically.
Unassigned items are not an error by default.
They simply indicate that a planning decision is still needed.
Planning always starts with unassigned Production Items.
Planning order and priorities
Within a Production Line, Production Items are executed in sequence.
The order matters because it affects:
start times,
finish times,
delivery performance,
changeovers and efficiency.
In Parallel Planning, you can:
change the order of Production Items,
group items logically,
adjust priorities based on delivery dates or production needs.
This allows planners to react quickly to changing conditions.
What “planned” really means
When a Production Item is planned:
it has an assigned Production Line,
it has a calculated Estimated start and finish time,
it is visible in the production queue.
Planned does not mean:
production has started,
production is guaranteed to happen exactly as planned.
It means:
“This is the current best production plan.”
Execution and reality come in the next step.
Common first planning issues
Production Item cannot be assigned or is not visible in unassigned
This usually means the material cannot be produced on the selected line or required material definition is missing.Planned times look incorrect
This is often caused by missing or incorrect master data definitions (shift or tact time definitions).
These situations are normal during initial setup and first use.
What you should be able to do now
After completing this step, you should:
understand how production planning works in P4,
know where to assign Production Items to Production Lines,
be able to create a basic production plan,
understand the difference between planned and executed production.
➡ Next step:
Managing the Production Queue: Replanning and Priorities
This is where you learn how to adjust the plan when reality changes.