Data integrity and quality - How do you get there?
Inspection Conditions
Inspection conditions include determining the inspection timing, personnel requirements and facility requirements.
Inspection timing is usually a contractual obligation that is tied to the time period between when the data is delivered
and final payment is made. The timing requirement and number of data deliveries (batches) will drive the personnel
and facility requirements. Personnel requirements typically include a Process Coordinator, Records Inspector, and
Database Inspector. Facility requirements will be based on the physical and logistical characteristics of the
inspection process including space and furnishings.
A Process Coordinator will be responsible for the process implementation and its continuous monitoring. This
person should have the following basic skills:
- Scheduling and resource management
- Comprehensive understanding of statistical principles and inspection processes
- Comprehensive understanding of the Client's sources
- Comprehensive understanding of the Client's Geospatial System Requirements
- Comprehensive understanding of contractual terms and conditions
A Records Inspector will be responsible for identifying and inspecting specific features and tallying those results.
This person should have the following basic skills:
- Familiarity with the statistical principals upon which the inspection process is based
- Comprehensive understanding of the Client's sources
- Comprehensive understanding of the Client's Geospatial System Requirements
- Ability to analyze source and conversion data and tabulate inspection results
A Database Inspector will be responsible for the inspection of the non-graphic database products produced in the
conversion. This person should have the following basic skills:
- Familiarity with the statistical principals upon which the inspection process is based
- Comprehensive understanding of the Client's sources
- Comprehensive understanding of the Client's Geospatial System Requirements
- Basic system navigation and file processing skills
The facilities requirements should be determined based upon the specific parameters of the project. How many
batches are going to be delivered over what time frame will determine most facilities requirements. Keep in mind
the following key points when determining your specific facility requirements:
- There will typically be many boxes of paper documents arriving with each batch that will need to be inventoried
and filed while the batch is being processed.
- The paper and data received for each batch will typically need to be saved for the extent of the contract.
- The inspection process will generate large amounts of documentation, which will have to be filed and stored for
the duration of the contract.
- Inspectors will require adequate work surfaces with sufficient room to layout D or E size drawings.
- Copy and FAX equipment should be available and in close proximity.
Characteristics To Be Inspected
Characteristics to be inspected will be specific to your projects requirements. Typically, you may want to categorize
characteristics into some General categories as well as some Feature Specific categories. Within each of these
categories, both major and minor characteristics will need to be defined. The major characteristics correspond to
critical product requirements that can lead to material defect in the geospatial application. Minor characteristics
relate to data non-conformities. This distinction will be critical when defining your acceptance criteria, as allowed
major characteristic errors will typically be much more stringent than allowed minor characteristic errors.
An example of how you might categorize your inspection characteristics could be taken by looking at a cable feature
in a telephony geospatial conversion. The cable feature would have some major characteristics such as whether or
not the feature was captured, whether or not it was captured along the correct side of the street, or whether its
database relationships are modeled correctly. If any of these major characteristics are captured incorrectly, they will
have significant affects on the usability of the data in its' various applications.
If the cable were not captured, then the connectivity for those cable pairs would be corrupted in all field side plant
from that point on as well as increasing the potential for a cut cable in the future. For these reasons, these types of
errors are weighted more heavily during the inspection. In order to account for the significance of the error and
provide the statistical results, these types of errors are counted as if all the attributes for this feature were converted
wrong. If a cable has been defined as having twelve attributes in the sampling scheme, then a missed cable would
result in twelve errors in the inspection tally. The same holds true for a cable captured on the wrong side of the
street. In some geospatial data models, this is a critical error and could cause cable cuts and added engineering and
construction costs due to the incorrect placement information. This example would also result in twelve errors
tallied during inspection.
