There are two main causes for production bottlenecks:
- Poor line balancing – some jobs are running slower than others, and materials pile up in front of the slowest ones.
- Poor process control and/or poor maintenance – the equipment does not run as it was designed to run. It is often down or busy re-processing materials.
In this post I'll focus on the first cause...First take a look at our new infographic on 5 Possible Cures To Production Bottlenecks: >> Tweet this production bottleneck infographic to your network if you find it useful <<
Further information on how to avoid production bottlenecks
In this article I'll focus on the first cause: a process step is slower than its upstream and/or downstream steps. We listed 5 ways to avoid bottlenecks in production.
The following examples are mentioned in the infographic, but there's some extra information given below:
- Common types of process improvement
Here are a few examples of things that you might have to look at and improve.
- You might need to set up the machine(s) and the operator(s) so the materials flow to them and don’t require much motion. Poor material presentation and an excessive need for handling can slow an operation tremendously.
- The machine may not be cycling properly – maybe 6’’ instead of a 3’’ cycle time. This needs fixing.
- Quality coming out of the process might be inconsistent, which means people might be spending time sorting and reworking everything before sending it to the next operation.
- The other processes might be much easier and their cycle times might be much shorter – in that case, remove people from the easy operations and add them to the slower operation.
- Example of product redesign
Up until recently, car manufacturers were placing speakers into a door with 5 screws. There was a snapping mechanism but it was not sufficient, and the speaker might rattle as the car was running.
Toyota designed the snapping mechanism well enough the speaker wouldn’t rattle and the 5 screws were unnecessary. That part was a bit more expensive but it saved a lot of assembly time and eliminated a production bottleneck.
- Thinking of adding resources
In point 1 we mentioned adding operators to the slower process. There are other ways to add resources.
One approach is adding another machine that does a bit of pre-work before the current machine (which then needs to do fewer tasks and can cycle faster).
For example, in a factory we helped three years ago, a shoe making machine was taking care of many tasks and had an 80’’ cycle time (including a long manual setup time). Putting the shoe form on before feeding that machine meant its cycle time dropped to 60’’. That led directly to 25% extra capacity for the whole line.
This type of improvement can often be done by a smart tool or by another machine.
- Automating the process further
Jumping to full automation places most Chinese factories in dangerous territory. Most of them don’t have good electrical engineers capable of setting up and maintaining high-tech machinery.
What we often put in place is a jig, a tool, or if necessary a robot, to position the material perfectly as it gets fed into a machine. Good mistake-proofing techniques make the process much faster and more accurate. Here are two examples:
- A jig that positions a steel part perfectly before it is cut;
- A go/no-go jig to be used on a wood drilling machine.
- Last resort… Subcontracting some work?
If the above solutions are not available/realistic, there is a relatively simple solution: setting up a “preparation line” on a side, which connects to the main line and feeds the materials as needed. It is often better than sending parts to an outside supplier and getting them back in (slower, usually more expensive, and involves some QC work).
Does this make sense to you? Have you seen other approaches that successfully elevated production capacity by elevating/eliminating a bottleneck operation?
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