Appendix C

Attach Point Symbolic Tags

Overview

Attach points do not have data fields or properties windows. However, they do have symbolic tags to use with commands such as addattach. Common tags are as follows:

Symbolic Tag	Meaning
<node>	The name of the node to which the attach point belongs.
<commodity>	The commodity that passes through the attach point into or out of the node.
<in>	Valid values are: True. This indicates an input attach point. False. This indicates an output attach point.

Some nodes also have bottom or top attach points.

Machine Node Attach Points for Modeling Setup Time

Instead of showing commodity flow, the attach point on the right side of a Machine or MachineDelta node lets machine time flow out as Reserved Time so that it can be consumed as setup in a Batch node. The attach point on the right side of a Machine or MachineDelta node connects to the attach point on the left side of a Batch node. When there is flow through the Batch node in a time period, demand for Reserved Time is created for the exact amount of Setup time specified in the Batch node; the amount of setup time is not scaled to the amount of flow. If the minimum run length of production is running in a time period, the Batch node should consume as much or more Machine time than the minimum run length.

You can also cost setup time by putting a cost on the arc connecting the Machine node to the Batch node. The cost on the arc is in addition to the cost of using the machine time. If you need setup constraints, enter the setup value in the Setup field of the Batch node. When you attach a commodity to a Batch node, a new attach point appears on top of the Batch node. You can draw an arc that joins the top of the Batch node to the setup attach point on the Machine or MachineDelta node. If you want to set a cost for using the setup constraint, enter the cost on the arc that joins the attach point at the top of the Batch node to the Machine or MachineDelta node attach point.

Storage-type and Monitor Node Attach Points

Storage-type nodes include Storage, StorageCover, StorageCoverLocal, and StorageDemand nodes. An attach point on the bottom of these nodes is an access point for the amount of inventory currently contained in the node. You can connect the bottom attach point to a Monitor node to set Maximum and Minimum levels for the total inventory contained in all Storage nodes.

Promotions Attach Point

The Promotions commodity enters a Promotion node through the attach point on top of the Promotion node.