The automotive industry first came up with the idea of
making cars on a conveyor belt. A takt line. Assembling is
done at certain stations, the line is balanced so that each workstation has an overall takttime.
One or several microbus tacttimers counting down towards zero. At the end of tact, the line of products move ahead one step. The movement can be made both manually as well as automatically.
Takt flow at the assembly lineDifferent kinds of takting system
Different kinds of productions is presented below. These systems could also be combined or parallel with the VisualCAT production system.
- Type A. A simple line with three assembly stations. All the working stations has the same takt time and the whole line takting at the same time.
- Type B. Two preparation lines are connected to a finishing line. All the working stations has the same takttime and all three lines are takting simultaneously. This system is configured in the same way as if all the three lines were one.
- Type C. This model is similar to type B, but the preparation lines are takting individually to each other and has its own takt times. This system is configured as one line with three preparation units/cells.
- Type D. This type of system is similar to type C and is configured as one line with four preparation units/cells.
In our systems, the term takttime is often defined as the time of a number of operations. This is also called cycletime.
Cycle time is defined as the time between two operations minus the planned downtime. The working operation could also be an assembly cycle or just any regular event depending on what should be analysed by the production system.
See also takted flow with split
In order to achieve efficiency for solving problems at the production line, the term andon is used. This means, when problems occurs at a working station, an andon button is used. Alternatively an andon string.
Andon/disturbance is announced to the other stations that are dependent of the actual place of disturbance, via the production screen. When all working stations have finished their operations, they can assist where the problem occurred. When problem is solved, the button is deactivated and the line tact to the next step. If andon button is not deactivated during tact time, the tact time will go negative and downtime will be accumulated to the shift.
Status of andon can be shown in the station overview. Stations with green-white status indicates that their operations are finished. Yellow-white indicates problem and in need of assistance. A description of what kind of problem that is indicated is shown the field of signals.
As addon for the production displays there are two different kinds of audio systems to configure. A software system that uses the computers´built-in audio routines or an external horn with three different sounds. Audio signals can be configured to sound at different events such as breaks, takt, andon etc.
Sound settings can be set individually for each line. Some audio signals are activated as a pre warning before another event. This time of delay is set for each event in the software under “time/s”. The signal devices´ serial communication module and its address is put in the field under signal device activation box. Length of signal, number of pulses and which of the three sounds that should be active, is set for each event on its own row in the software.
Balance the line
The work with dividing the different operations so that all sub operations for each station has the same time, is called balancing the line. Our systems assists in measuring and visualising how well the line is balanced. Each station is then provided with an andon button.