Getting started

This example is the same one shown on the website: two orders, X and Y, made on two lines and then assembled.

1. Resources

Resource	Capacity
Line 1	1 task at a time
Line 2	1 task at a time
Assembly	1 task at a time

2. Tasks and orders

Task	Order	Resource	Duration	Goes after
X1	X	Line 1	2 h	—
X2	X	Line 2	1 h	—
X3	X	Assembly	2 h	X1 and X2
Y1	Y	Line 1	1 h	—
Y2	Y	Line 2	2 h	—
Y3	Y	Assembly	1 h	Y1 and Y2

3. Rules

Rule	Type	How it is expressed
Precedence	Hard	“Goes after” on each task
Capacity	Hard	The capacity of each resource
Material: the sheet metal arrives at 10:00	Hard	Earliest start of the line tasks
Stoppage from 13:00 to 14:00	Hard	A fixed block on each resource

4. Objective

Finish as early as possible: the Makespan objective.

5. The plan

Resource	Plan
Line 1	X1 10:00–12:00 · Y1 12:00–13:00
Line 2	X2 10:00–11:00 · Y2 11:00–13:00
Assembly	X3 14:00–16:00 · Y3 16:00–17:00

Without the material rule the plan would start at 8:00, and without the stoppage rule the assembly of X would fall in the middle of it. Each rule discards plans that cannot be executed: that is what figure 2 on the website shows.

Next steps

• How to describe resources with capacity and plants: Resources.
• Alternative routes, minimum waits and repetitions: Tasks and processes.
• Due dates and penalties: Orders and dates.