[Plant Simulation Tutorial #04] – Using MU (Movable Unit) and Attributes Effecti

✍️ [Plant Simulation Tutorial #04] – Using MU (Movable Unit) and Attributes Effectively

 
📑 Summary
In this post, we introduce Movable Units (MUs) — the core elements that represent flowing items such as products, components, or raw materials in Plant Simulation. We'll also explain how to assign and utilize Attributes to make each MU behave dynamically and realistically.

---

🔍 1. What is an MU (Movable Unit)?

Attributes - 속성

An MU is a dynamic entity that flows through your simulation model. In real-life manufacturing, this could represent parts, products, materials, or subassemblies.
MUs come in two primary forms:

TypeDescription

MU	Represents a single part or product
Container	Represents a carrier (e.g., pallet, box) holding multiple MUs

 

---

🔧 2. Attribute – Assigning Properties to MUs
🧩 Attributes Panel View
By assigning Attributes to MUs, you can give each unit a unique set of data or states. This allows for differentiated logic — for example, distinguishing between Product A and Product B or tracking quality level and priority.

SyntaxDescription

MU.AttributeName	Access a property on the current MU
AttributeName := value	Assign a value to that attribute

 

 

💡 Pro Tip:
You can create custom attributes using the User-defined tab in the MU class.
Example:

• Name: P_xlength
• Datatype: length (m)
• Value: 0.5

 
This allows each MU to carry product-specific metadata like dimensions.

---

🎯 3. Attribute Usage Example
Let’s create a simple logic where:

• The Source generates an MU with a random setting value between 1 and 10.
• The Station adjusts processing time based on this value.

Source → [Exit Control: Front]

-- Generate random setting between 1 and 10
var A : integer := z_uniform(1,10)
@.setting := A

-- Required move command for Front ExitCtrl
@.move

Station → [Before Entrance: Entrance Control]

-- Assign processing time based on MUs setting

if @.setting = 1 or @.setting = 2 or @.setting = 3
  ?.proctime := 10
  print "Processing time is 10 seconds."
else
  ?.proctime := 5
  print "Processing time is 5 seconds."
end

 

🧠 With this logic, you can simulate process time variation based on product type or status.

---

📦 4. Common Use Cases for Custom Attributes

Use CaseExample

Product type	MU.Type := "LCD"
Urgency flag	MU.Urgent := true
Quality grade	MU.Grade := "B"
Due date	MU.DueDate := 2024.07.31

 

These values can be used throughout the simulation logic for sorting, routing, prioritization, and more.

---

📘 Advanced Tips

• Use EntranceControl, ExitControl, or Method tabs to implement attribute-based logic.
• Attributes work well with logical elements such as Sensors, Sorters, or Decision Points.
• You can link attribute values to Tables for external data-driven decision-making.

---

📝 Conclusion
Mastering MUs and Attributes allows you to build flexible and dynamic simulation models.
You’ll be able to simulate complex product variations, priority-based routing, and condition-dependent flows — turning Plant Simulation into a true digital process analysis platform.

---

🔜 Next Post Teaser
In [Plant Simulation Tutorial #05], we will dive into ExitControl and SimTalk scripting, showing you how to take full control over the MU flow in your models.