The placement of the Workstation sees the exact definition of the volume of the locations of the various work Position and equipment in the space provided.
We will go into the details of the location of the Workstation. Typically, if we have chosen a seated Workstation , it will be necessary to anticipate the fact that the Position is located in an area where the operator will not need to travel. This requires either that the Mizusumashi takes everything on the Workstation, or that the work Position are side by side.
1 – Define the overall location of the Workstation
Through a VSM, we will define all the steps of added value. Thanks to this cartography, we will know where our Workstation is in the process and let us have a good idea of its geographical location. Without specific constraints related to standards, unsuitable buildings or otherwise, the criterion of limiting the movement of parts is paramount.
It is at this moment that one must ensure the presence of the energies at disposal : electric, pneumatic… This is a critical issue if you realize that at the time of installation.
The mapping of the flow should allow us to situate the different stocks and buffer of production. In a just-in-time logic, we will avoid the reflex of systematically predicting a location of a pallet to avoid organizational dependencies.
Calculating a Buffer
In a logical just in time, we will avoid as much as possible the buffers. However, for continuous flow processes or tasks where we do not know how to limit the variability, these buffers will be necessary.
The function of a Buffer is to limit the impact of the rate loss of the upstream process on the downstream. For example, for a line composed of 4 machines in series, without buffering the overall performance is the multiplication of OEE of each of the equipment. With a rate of 95%, we will therefore have an overall efficiency of 95% * 95% * 95% * 95% = 81.4%. Without buffering, the performance decreases rapidly.
To limit this effect, the Buffer will be calculated according to the MTTR Equipment.
The machine broke down. The average time to reboot is 10 minutes. During these minutes, the machine B will have consumed 100 Parts, which must be added the number of Partthat the machine B will have consumed between the restart of the machine A and the time that the Part arrives at the Machine B.
The storage areas must be planned according to the flow of parts, but also the accessibility. Thus, the parts fed by Mizusumashi Will preferably be accessible directly from the aisles to avoid unwanted manipulation by the tanker.
3-The volume of the Workstation
Freedom of movement within the Workstation is a preponderant criterion. Beyond obvious productivity problems, a difficult circulation will generate additional fatigue, nervousness and quality problems.
The German standard DIN 33402 gives guidance on the spaces necessary for good circulation. The diagrams below give some typical work situations and the minimum dimensions in cm to ensure good working conditions.
From these measures, the overall ” minimum ” Dimension of the Workstation will be defined.
4-the ” levels ” of the Workstation
Now that we have a good idea of the configuration of the Position, we will define the different heights of circulation of the parts. We will begin by identifying the flow of the main parts, their entry and exit level. The challenge is to facilitate the transfer of parts, especially heavy parts. For this we can :
- Use the gravity of the object via slides, dynamic rails, or ball tables for example.
- Avoid level changes between 2 consecutive posts, specifically if the parts are heavy or large.
- Provide handling aids (load balancer, mobile service,…) for displacement if rail systems are not possible.
To respect the fact of changing the level, it will be necessary to raise the Workstation or part of the Workstation. Although not recommended, this elevation must follow the following rules.
Elevation with step
Elevation with slope
It is essential that a Workstation is not ” isolated “. Firstly, to ensure good coordination between the different positions of the same line but also to improve the passage of instructions and the synchronisation of work.
Then it has to have easy access to means of communication for example call maintenance, safety or quality if necessary.
It is necessary to list all these necessities in relation to your case and then to foresee the necessary means and locations: telephone, glazing…
C. Hohmann (2009) – Productivity Techniques, how to earn performance points