Before you want to start your workflow, you can run a test to measure its operativeness. To do this, swap to the workflow tab and click on the Validate menu item. A dialog opens, where you can see if there are any errors in your process model. Of course, no errors should be displayed if you want to start a workflow.
After that, the process needs to be deployed. Go to the Publish tab and in section Process click Deploy Process.
After deploying, the workflow can be started. If you want to have the possibility to start a workflow over the Process Portal, the process needs to be published. There are different ways to start a workflow. Most of the time a workflow will be started manually or triggered over a business entity, or with a timer event. How the workflow is started depends on the configuration of the start event. If no event is configured, the workflow has to be started manually. When a business entity is configured as a start event, the workflow can be triggered for example with adding an item in a SharePoint list. It is not uncommon that workflows should be triggered at a specified date/time, so therefore the timer event is used. Last but not least the workflow can be triggered over internal and external events as well.
When starting a workflow manually you have two possibilities to do so. You can either go to the Publish tab and click Start Process under the Process section.
Or you use the Process Portal to start a workflow, which is the second possibility. But this can only work if the process has been published before. In the Process Portal you find the process under Startable Processes. Select the process you want to execute and click Start.
As soon as a workflow is started, there exists an execution of this workflow which can be viewed under Workflows in tab Running. With double-clicking the execution, you can check the progress the workflow made so far. When the workflow is finished, it can't be displayed under the Running tab anymore but under Finished now.