The inspector will normally be able to complete the inspection without checking all the checkpoints in the checklist. However, if certain points should always be checked, you can set the checkpoint to Mandatory to fill in like below:

Similarly, you can require the inspector to take pictures for a checkpoint by selecting the Mandatory to take pictures option. 

In the mobile app, if the inspector tries to finish the inspection, the missing points will be highlighted as follows:

If the inspector cannot fill in the information (for example, if you have a checkpoint to check inner packaging, and the product does not have an inner pack), the status can be set to Not applicable, and the report can be submitted.

If it is mandatory to take pictures, the camera icon will all show up in red if the inspector tries to finish the report without taking a picture, as illustrated below: