After deploying a model, you can alter it. You can do this by making changes in Model mode and then redeploying. You can also alter your deployed application in Sybase Central Admin mode or by directly changing the database using system procedures or other methods. However, when you alter a deployed model outside of Model mode, you cannot reverse-engineer the changes back into the model. When you redeploy the model, changes to your synchronization application that were made outside the model are overwritten.
If you make any changes to the schema of the remote or consolidated databases, you need to update the schema in the model before you redeploy. Deployment often causes schema changes, so you may need to update the schema even if you haven't made any other changes. For example, if you deploy a model that adds a timestamp column to each synchronized table on the consolidated database (which is the default behavior when you create a model), you need to update the consolidated schema in the model before redeploying. Likewise, if you add a table to the consolidated database and then want to redeploy, you need to update the consolidated schema in the model and then create new remote tables.
To run the Update Schema wizard, choose File > Update Schema.
See Updating schemas in Model mode.