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2.3 Waiting Time

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This page has relationships - Parent page: 2 Definition of Time
2.3.1 Definition Waiting Time: The machine (is) stopped and has to wait for something, although in it selves -technically speaking- it would be able to run. It is waiting for something to become in order before it can produce again.

Having [no input] or [no output possible] due to restraints in the line/chain/flow is considered to be a separate group of time (Line Restraints).
2.3.2 Categories
No Time Usage Max. recommended Time Type
20 Setup 5 P F W L
  • Product change
  • Setup
  • Quality Change
A setup in terms of OEE lasts from the last product X until the first product Y, regardless its quality.
Caution: This is different from the SMED definition: Last GOOD product until first GOOD product!
Depending the situation it might be useful to precede or succeed the setup time by a shutdown and startup category, to visualize in a Pareto where the main losses of setup are to be eliminated.
21 Startup/Shutdown 2 P F W L
  • Heat up
  • Start after stop
  • Run-in
  • Checking machine
  • Preparation
  • Pressurize
  • Pump dry
  • Empty out
  • Clear out
  • Rinse out
  • Cool down
  • Calibration
The machine is not producing due to the fact that it has no vertical startup or shutdown.
This can occur at beginning or ending of shift but also before or after a setup or repair works. This time is defined separately from the main reason to shut down the machine.
Cleaning belongs here if it is part of the startup or shutdown activity, including startup of a new product (process-cleaning).
22 No Operator at machine 5 P F W L
  • Break
  • Meeting
  • Training
  • Help at other machine
  • ‘Washing hands’
The machine is available, but is not running because the operator is not operating it for example during his break, a training or a meeting.
23 Quality problems – Process disturbance 2 P F W L
  • Stopped because output is out of spec
The machine cannot run because the process cannot meet up with the specifications for (at that moment) unknown reasons.
If the reason is known (i.e. bad raw material), it should be registered as such (Bad raw material = Waiting for correct material).
24 Refill/Replace 3 P F W L
  • Blade change
  • Refill ink cartridge
  • Oil Refill
The machine is stopped while refilling or replacing auxiliary, e.g. cutting blades, coolants, ink, oil, etc.
25 Loading 3 P F W L
  • Load labels
  • Load boxes
  • Load Raw material
The machine is stopped while refilling/loading raw material, e.g. packaging materials, foils, and other raw materials.
26 Handling 2 P F W L
  • Truck (un)loading
  • Forklift driving
  • Container change
The machine is waiting while required material is being handled.
This is a more specific situation from the ‘Waiting’ block.
27 Waiting 7 P F W L
  • Waiting on Tooling
  • Waiting on Engineering
  • Waiting on Maintenance
  • Waiting on Inspection
  • Looking for Gauge
  • No/Bad Packaging
  • No/Bad Raw material
The machine is not running because the correct raw material or a tool is not present at the moment it is needed, or an action cannot be performed.
In this block we find reasons for waiting that are caused by a weak planning. In the block ‘No Resources and No Personnel’ the reasons are ‘Force Majeure’.
Consider carefully to define lack of raw materials as Line Restraint to reveal line-balancing and supply chain problems! Is it a capacity (=balancing) problem or just a handling or organizing issue?
  • No operator Available
It might occur we forgot to schedule or replace an operator.
28 Autonomous Maintenance & Cleaning 3 P F W L
  • Shift Maintenance
  • Daily Cleaning
The main reason why the machine was stopped was due to AM activities, including cleaning.
When a machine is being cleaned in the time it was standing due to another reason (i.e. waiting for raw material) the primary reason why the machine is standing is being registered.
Process cleaning (like rinsing between two products) belongs to startup-shutdown.
29 Preventive Maintenance during Loading Time 2 P F W L
  • Planned PM during Loading time
Scheduled time to perform PM.
  • Unplanned PM
The machine is stopped at a not scheduled moment to perform PM or the machine is stopped at a scheduled moment but exceeding the scheduled time to perform PM during a scheduled time.
PM happens ‘in process’; it is scheduled in the production sequence and needs to have a balance between enough and not too much. If well performed, the planned maintenance time will reduce the unplanned breakdown time. And most important: It is predictable time.
2.3.3 Principle
If two or more time-usages occur at the same time, the primary reason for stopping is being registered
Example: Cleaning while change-over: The change-over is the primary reason to stop
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