Frequently asked questions

The dynamic property in accumulation (or buffering) indicates that the system can react to (in other words, absorb) speed variations between the machines its connected to on the fly. If one of the two machines runs either faster or slower than the other, the dynamic accumulator can instantly speed up or ramp down and start accumulating products or feed out more products when nessecary. This prevents jams, stops or other disruptions from happening in the up or downstream of the connected machines.

Most accumulators need to manipulate the product in order to either accumulate or release them back into the main flow. Some more advanced accumulators now have the unique feature of being able to switch from accumulating products to releasing them without the need to touch them. This further increases the range of possibilities especially so in the case of fragile or oddly shaped products or packages.

Sequential means that the order of products in the line stays the same throughout the whole process. Products stay in sequence and can be accuretely traced. This is very important when handling food (amongst other things). If for example a certain batch has to be recalled due to contamination its necesarry to be able to trace it. Alternatively, non-sequential means that products do not follow a strict production order. Products could switch places and be handled in a different time or order than originally produced (due to offline buffering for example). Examples could be the printing of magazines, or toilet paper etc...

Upstream in manufacturing refers to processes that occur before or earlier on in a production sequence or production line relevant to the point in process refered too. Downstream in manufacturing refers to processes that occur later on in a production sequence or production line relevant to the point in process refered too

Overall Equipment Effectiveness is a measure of how well a manufacturing operation is utilized (facilities, time and material) compared to its full potential, during the periods when it is scheduled to run. It identifies the percentage of manufacturing time that is truly productive. An OEE of 100% means that only good parts are produced (100% quality), at the maximum speed (100% performance), and without interruption (100% availability).

These are several products tightly spaced together coming through the process. For example, when an x number of filled bottles/packs/jars/pouches come out of the filler together and are put on the conveyor, before the next batch of X products are filled. The products then move as a slug on to the next part.

The gap in between two consecutive products in a line

Mean time between failure. Mean time between failures (MTBF) describes the expected time between two failures for a repairable system.

In a paced line the time allowed for an operator or machine to work on the job is limited. Once the time is up the job can be no longer worked on, and thus it is possible that the processing is not completed when the job moves on. In an unpaced line there is no maximum limit imposed on the processing time available to the operator or machine.

With pressure accumulation (or buffering) the conveyor or system that receives and holds the products does this in a way that slowly builds pressure between the buffered products (also known as backpressure). Some products can perfectly handle pressure when buffered or accumulated. Other products can be damaged by the pressure or worse, break. On the other hand, with a zero pressure accumulation (or buffering) the products are accumulated in such a way that it avoids the producsts building up pressure. The products are stored in such a way that they don't touch each other.

First in - First out means that the first product that enters the machine is also the first one to leave again. This usually means that the product sequence stays intact which can be a critical feature for various types of productions. An example could be batch tracing within liquid filling or pharmacy. Alternatively, First in - Last out means that the first product that enters the line is that last one to leave when the products are fed out of the system. These types of systems can be cheaper, and could be used in system where a set sequence isnt relevant. An example could be non-perischable products or those that don't have time sensitive processes.

An inline system is a machine with an inline process product stream from the main line of a packing or filling system. With an offline process the product stream goes through a bypass from the main line of a packing or filling system and could be fed back in the line down stream

Work in process refers to: materials that are turned into goods within a short period, that are currently in the process of going from raw materials to finished product. It can also point at those specific processeses that cant stop without consequences for the product. For example, some parts like heat treatment, foil welding, conditioned air packing, gluing, etc., need to run empty to avoid waste products or equipment damage.

The least efficient machine in a line. This machine has the most impact on the output of the line and should always be protected against stops, jams or other issues.

When a machine has an intermittend outfeed it means it releases discontinuous flow of products (instead of a continuous flow where a stream of products come out in a steady pace).

Increasing the time it takes for the product to reach the next step or process in the line

In synchronous lines the movement of jobs is coordinated; all jobs move to the next work station simultanuously. So the number of jobs in the system remains constant, and there is no need to put buffers in between stations. This type of production line may be further split up between paced and unpaced lines. In asynchronous lines the movement of jobs is not coordinated. The operator or machine starts to process the next job as soon as one becomes available. And on service completion the job immediately moves to the next work station, as long as there is space for it. Thus an operator or machine can become starved (no job available) or blocked (no room to put a completed job). Asynchronous lines are almost always unpaced. The number of jobs in the system may fluctuate (considerably) and buffers are needed to prevent starvation and blocking (i.e., loss of capacity) as much as possible