Update design/20200516-dependency.md

Co-authored-by: Ryan Zhang <[email protected]>

design/20200516-dependency.md

@@ -64,7 +64,7 @@ They have strict ordering:
 preprocess -> training -> serving
 ```
 
-Without the previous stage finished, the next couldn't start due to lack of data.
+Each component has to wait for data to be finished processing by the previous stage.
 Today, ML frameworks including Tensorflow do not handle such dependency issue.
 They rely on external tools (e.g. Argo Workflow) to handle it.
 If we want to model them as Components in the same ApplicationConfiguration, the external tools could not help in this case.