You can manually anchor lines to symbols so that when you move the symbol, the line stretches to stay attached to it. Many SmartTemplates that use Automatic Shape Connectors, such as Flowcharts and other similar visual types, will connect symbols for you.
To ensure your symbols connect, you must:
This anchoring ability is already turned on in most SmartTemplates, but in some it’s not.
To ensure it's enabled, click the SmartDraw button
located in the top left corner of the window.
Position your cursor over Options and ensure the first checkbox button
, is checked.
Now choose the line shape (How?) you’d like to connect the symbols with. Click on the edge of one of the symbols then draw the line to the other symbol.
As you approach the second symbol, round black connection points appear along its border, and your cursor becomes an anchor-shaped icon. This anchor indicates that releasing the mouse button will anchor the line to the desired connection point of the shape.

To disconnect a line from a shape, click on the line. Then click on the round, black handle where the line meets the object and drag the line away.