The six major efficiency areas

The purpose of measuring efficiency is to be wise to where things are going less well.

After that, it is often obvious where to start an optimization process.CASESThe six major efficiency areas

The efficiency measurement can be divided into three groups:

1. Availability
2. Production speed (Performance)
3. Quality

To each of the three points we can add two sub-points, and then we have a total of six groups. These are the normal main reasons for low efficiency.

Unavailability can be broken down into scheduled stops (setup and adjustments) and unplanned stops (Equipment or production failures).

Low production speed can be the sum for many small reasons (waiting time and small stops) or problems with, for example, the condition of the machine or the operator’s routine and experience (reduced production speed).

Quality problems can be divided into two groups, one being start-up scrap (quality loss during start-up) and manufacturing errors (loss of quality during stable production).

Remember that efficiency can be defined as Overall Equipment Efficiency or just OEE.

The formula is Availability x Performance x Quality = OEE.

Therefore, let us take a quick look down into the three topics to get a slightly better overview.

1. Setup and adjustments

These are planned stoppages in production. Setup and adjustment can include both larger and minor adjustments, cleaning, heating, planned maintenance and quality inspection.

The time can be measured by the entire category, or you can divide into relevant subtasks. Setup and adjustment cannot be eliminated, but one can consider whether the entire time spent is relevant or whether individual processes can be improved.

Often it is the setup to produce a new type of item that takes the most time.

2. Equipment or production defects

Time spent because machinery or other equipment fails often results in a large loss of production. Moreover, it is always inconvenient for equipment to break down instead of being maintained in time.

Unplanned stops can be caused by defects in a machine, in belonging to tools, lack of an operator or lack of materials.

One should always consider whether there is a malfunction in production or just a minor stop (see below), and it may be a good idea to put on a duration. For example, all stops under two minutes can be defined as “minor stops”, while stopping over two minutes is an error in production.

3. Waiting time and small stops

Minor stops are the category of machine stops, where the duration is typically a minute or two. It may be that a subject has stuck, that a setting needs to be adjusted, that a sensor is blocked or a lightning-fast cleaning.

Because the small stops happen so often, you may find it difficult to measure them, and therefore you can also become blind to the overall effect of all the small disturbances.

4. Reduced production rate

The maximum production speed is the starting point for assessing whether production is running fast enough. Of course, no machine runs at full pace all the time, so it is important to define what is the realistic, maximum pace of a machine.

Speed can decrease due to worn-out equipment, dirt, lack of lubrication, lack of experience of the operator, poor quality materials, transitions to new shifts, start-up and decommissioning of production.

5. Quality loss during start-up

When a new production is started up, there will often be a loss of quality within stable production.

This can both cause items to be discarded or items to be re-produced. In the definition of OEE, quality is measured in the first test, so a new production of the same subject also counts as a loss of quality.

Loss of quality during start-up is often due to the fact that the switching process is not optimal, that it takes time to hit all settings perfectly, and then there are types of equipment that simply cannot produce perfectly before a certain start-up period.

6. Quality loss during stable production

During stable production, there can still be a loss of production. Equipment can be set up incorrectly, the operator can make a mistake, materials can break for no particular reason and in some types of production the date of use of materials can also be exceeded.

Use common sense

It may be a good idea to define waste causes per machine, because machines are not the same.

Opticloud comes with a configuration option where you as an administrator can make settings for each machine. In this way, the operator can enter a stop reason manually in cases where the machine cannot automatically tell you why a stop occurred.

When you have a comprehensive overview of spill causes per machine it is a good starting point to understand where to start.

Often there are underlying causes that create waste in many parts of the system. Have you invested in the right machines? Are operators trained well enough? Are materials of the right quality used?

Understanding data is the first step towards more efficient production.