For this walkthrough, consider a use case where data on the structural integrity of a number of buildings needs to be gathered and analyzed. This data can only be collected between the hours of 9 am and 5pm daily in the months of February and March 2016. Data and time related input values are to be stored in their respective Coordinated Universal Time or UTC equivalent. Where defects exist on a buildings, photos are required to be taken and the exact area of defect clearly marked in the photos. Along with these photos, the building code should be scanned, a photo of the building signboard should be taken as well as the date and time the data was collected. The data collector must also acknowledge that the data inputted into the form is correct and true.
During and after data collection, an analyst, among other things, should be able to compute the number of buildings with defects and see photos of these defects. Than analyst should also be able to query and view the signature of each building manager as well as photos of building signboards. The analyst should be able to carry out other computations besides. If data submitted to the server is found to be suspect, the analyst should have a means to identify the source of the data i.e., the device from which the data came and possibly the data collector.
From the details of the last section, the following data input fields and constraints for the form are deduced:
All inputs for the form are compulsory except for the situation described in item 7 below.
The form must provide a means by which photos of building defects and signboards are captured.
The form should allow the data collector to take as many photos of defects detected.
The form should allow photos taken of defects to be marked or annotated.
The form must provide an input screen that allows for the collection of signatures.
The form must allow for the scanning of bar codes, QR codes etc.
Where a building does not have a defect the form should hide or skip the input screen for capturing photos of same.
The form should restrict the survey time input to 9:00 – 17:00.
The form should also restrict the survey date input to February and March 2016.
The form should provide an input screen where the data collector can acknowledge that data inserted into the form is correct.
The rest of this walkthrough is structured thus:
Designing the form with the constraints listed in the last section.