**2.2 Model material feed scenarios in the factory**

The success of the production process is influenced by the role of the material supply scenario in the factory [26, 27], and with a good scenario, it can be ensured that each station receives a timely supply and is easily handled in the production process, because each component is in a standard container rack, trolley, and box (RTB) and in a continuous range of motion so that the operator's movements are merely productive movements to produce added value, while nonproductive movements without producing added value must be kept as low as possible.

The basic principle of supply is to pull in complete quantities. This means that the supply of each process must be complete to form a one-piece flow, and after the material in the WIP buffer is finished, the supply can be withdrawn to the workstation, thus ensuring that the finished goods can be formed because each component is available.

**Figure 2.** *Planning horizon of the production model D minus 1.*

The concept used to fulfill these basic principles is to supply feeding materials to each workstation in the form of lots, batches, or kits. **Figure 3** shows the scenario scheme of the material supply to produce one type of bed. In this case, the production control area is only in the area bounded by the red line; outside of that is the supplier area, and in this case, the supplier is considered capable of meeting the supply requirements as required by his customers.

Starting from the upstream supply, suppliers for metal components in the form of raw components must supply to the welding station in the form of lots, which are placed in a standard RTB for processing at the welding station. The output of the product welding station is sub assay, and the product is placed in a standard RTB in smaller quantities, that is, batch and fed at the paint station.

Furthermore, the results of the paint station are placed in a standard RTB and forwarded to two workstations, namely, the component module station and the final assembly station. The supply of plastic components in batch form is supplied to the component module station and final assembly. The caster wheels are supplied in batches directly to the final assembly station.

The existing supply in the factory is in the form of standard module components and standard component stations. From the station module components are supplied components such as thrusters, side guards or head end foot panels in batch units. Whereas, the supply of standard components is in kit units. The management of this kit form is done in a standard component warehouse.

The production scenario starts with the planned activity at the final assembly station with the production schedule on day 0 (day zero D0) followed by the welding supply time scenario supplied on D-2 (minus 2 day) so that the production schedule is complete, and the supply at the paint station must be available on D-1 day (minus 1 day).

**15**

**Figure 4.**

*Production model scenario D minus 1.*

*D Minus 1 Production Scenario: Production Model for Produced Hospital Furniture*

of bed products, and the process timing is shown in **Figure 5**.

This section explains the WIP buffer model in the D minus 1 production scenario shown in **Figure 4**, which illustrates the configuration of work-in-process management (WIP) in the form of the production process of making beds for various types

In **Figure 4**, welding stations there are various stations from M11 to M1n, in the paint section there is only one M2 station, while in the assembly station various stations are available, namely, M31 to M3n, each station produces a certain type of

All workstations are controlled by the WIP buffer, and the buffer configuration at the factory is from the B11 feeder to B1n which is the WIP buffer from the M11 to M1n welding station. While the feed in the paint section for the M2 station is controlled by the WIP buffer continuously at buffer B21 to B2n. The output from the paint section continues to hold the WIP buffer from B31 to B3n and the buffer is prepared for the M31 to M3n assembly station, and the result is the finished product

The results of welds from various welding stations cannot be added to the paint section at once, because operations in the paint section are dependent on the hanging effortability of the components to be painted. Each component to be painted is hung on a hanger, and then through the conveyor the components are processed one by one. From the start of hanging until the first component out of the oven takes 90 min, and for a conveyor speed of 2 m/min, a set of products requires time to leave the paint section between 6 min and 12 min, depending on

The output from the paint section must be able to feed the M31 to M3n assembly stations in accordance with the specified production schedule. If the buffer to the assembly station is done together with the painting station, the M31 station needs to wait 1.5 h (the first product waiting period comes out of paint station) plus 60 min (to complete one full provision of one batch of five component sets) while the

*DOI: http://dx.doi.org/10.5772/intechopen.93691*

**2.3 WIP buffer model**

in buffers B01 through B0n.

the complexity of the product.

product.

**Figure 3.** *Material supply scenario.*

*D Minus 1 Production Scenario: Production Model for Produced Hospital Furniture DOI: http://dx.doi.org/10.5772/intechopen.93691*

### **2.3 WIP buffer model**

*Concepts, Applications and Emerging Opportunities in Industrial Engineering*

supply requirements as required by his customers.

in batches directly to the final assembly station.

D-1 day (minus 1 day).

smaller quantities, that is, batch and fed at the paint station.

of this kit form is done in a standard component warehouse.

The concept used to fulfill these basic principles is to supply feeding materials to each workstation in the form of lots, batches, or kits. **Figure 3** shows the scenario scheme of the material supply to produce one type of bed. In this case, the production control area is only in the area bounded by the red line; outside of that is the supplier area, and in this case, the supplier is considered capable of meeting the

Starting from the upstream supply, suppliers for metal components in the form of raw components must supply to the welding station in the form of lots, which are placed in a standard RTB for processing at the welding station. The output of the product welding station is sub assay, and the product is placed in a standard RTB in

Furthermore, the results of the paint station are placed in a standard RTB and forwarded to two workstations, namely, the component module station and the final assembly station. The supply of plastic components in batch form is supplied to the component module station and final assembly. The caster wheels are supplied

The existing supply in the factory is in the form of standard module components and standard component stations. From the station module components are supplied components such as thrusters, side guards or head end foot panels in batch units. Whereas, the supply of standard components is in kit units. The management

The production scenario starts with the planned activity at the final assembly

station with the production schedule on day 0 (day zero D0) followed by the welding supply time scenario supplied on D-2 (minus 2 day) so that the production schedule is complete, and the supply at the paint station must be available on

**14**

**Figure 3.**

*Material supply scenario.*

This section explains the WIP buffer model in the D minus 1 production scenario shown in **Figure 4**, which illustrates the configuration of work-in-process management (WIP) in the form of the production process of making beds for various types of bed products, and the process timing is shown in **Figure 5**.

In **Figure 4**, welding stations there are various stations from M11 to M1n, in the paint section there is only one M2 station, while in the assembly station various stations are available, namely, M31 to M3n, each station produces a certain type of product.

All workstations are controlled by the WIP buffer, and the buffer configuration at the factory is from the B11 feeder to B1n which is the WIP buffer from the M11 to M1n welding station. While the feed in the paint section for the M2 station is controlled by the WIP buffer continuously at buffer B21 to B2n. The output from the paint section continues to hold the WIP buffer from B31 to B3n and the buffer is prepared for the M31 to M3n assembly station, and the result is the finished product in buffers B01 through B0n.

The results of welds from various welding stations cannot be added to the paint section at once, because operations in the paint section are dependent on the hanging effortability of the components to be painted. Each component to be painted is hung on a hanger, and then through the conveyor the components are processed one by one. From the start of hanging until the first component out of the oven takes 90 min, and for a conveyor speed of 2 m/min, a set of products requires time to leave the paint section between 6 min and 12 min, depending on the complexity of the product.

The output from the paint section must be able to feed the M31 to M3n assembly stations in accordance with the specified production schedule. If the buffer to the assembly station is done together with the painting station, the M31 station needs to wait 1.5 h (the first product waiting period comes out of paint station) plus 60 min (to complete one full provision of one batch of five component sets) while the

**Figure 4.** *Production model scenario D minus 1.*

**Figure 5.** *Timing process in production model scenario D minus 1.*

other station waits because there is no buffer. This is a situation where the buffer is not sufficient to supply an assembly station that is designed to operate at a certain capacity.

To overcome this, a buffer scenario is created on day D--2, where sufficient buffers must be available from B11 to B1n to be fed to the welding station. Meanwhile, to be fed to the paint part, there must be enough buffers B21 to B2n available. Furthermore, to be fed to the assembly station, B31 to B3n buffers must also be available in sufficient quantities.

The buffer that needs to be provided is work in. This buffer must be ensured on day D-3 already available, while through the WIP controller the input entered into the system must be controlled, the input is work released, while the throughput is work out provided from the WIP buffer of finished goods B01 to B0n.

Through this model, it can be stated that the controlled parameter is WIP in the system, while the manipulated parameter is the upstream buffer in each machine system of the three processing machines. By using the principles of control, of course by controlling WIP through the manipulation of parameters of the production process, it is expected to succeed.
