| Product(s): | WaterSight |
| Version(s): | 10.00. |
| Area: | Documentation |
Workflow
1) Definition of the key aspects or criteria
Definition of the key aspects that can drive pipe prioritization. The user can choose any aspect taking into consideration both the data available and imported into the solution as well the specific context and requirements of the utility and the region. Those can include (but not limited to): pipe age, material, break rate, pressure changes, customers affected, diameter, proximity to main roads, etc.
Aspects can be defined in order to contribute to the likelihood or consequence of failure, and can be based on the original information provided in the pipe shapefile, hydraulic model results or other contextual information. More information is available under the likelihood and consequence of failure help pages.
Creating aspects using the decision tree method is the most flexible and customizable methodology, that can be applied to any water utility requirement or constraint.
2) Calculating the scores for each aspect using a user driven approach
Individual scores for each pipe are defined by the user based also on user defined conditions. This can be done by using the decision tree method or in a simple way by creating a Predefined, and choosing the score type Discrete.
The decision tree method is composed by the conditions and the results or scores for each condition or group of conditions. For each condition it is possible to employ flexible and customizable rules, by creating user defined and detailed queries across multiple datasets. More information about the decision tree can be found here.
Figure 1 - Example of applying a decision tree to score pipes based on user defined rules.
In a more simple way, when the user wants to individually score each aspect, it is also possible to go for the Predefined Method, and choose the Score type Discrete.. In this case the user will need to define the range of values (if field is numeric) and the respective scores. Two examples below.
| Discrete score for numeric type field | Discrete Score for string type field |
3) Combining different aspects together
After the key aspects are defined (1), and scores for each pipe and aspects are calculated (2) the user can combine multiple aspects together together to build his multi-criteria decision ranking system. The multi-criteria decision ranking system is composed by the different key aspects (and scores) as well as the weight for each aspect. It is also possible to combine aspects that were created using data driven methods with aspects that were created through a user driven approach. The final pipe score is obtained doing a weighted average of the individual pipe scores for each aspect.
The software is flexible enough for the user to be able to include every key aspect in the same decision ranking system (mixing risk - likelihood and consequence of failure - with asset performance) or by creating a ranking system to separately assess likelihood of failure (LOF) and another ranking system to assess consequence of failure (COF). Then the user can combine both LOF and COF results to calculate the risk score using a risk matrix.
Below an example of a multi-criteria decision ranking system, with the aspects and respective weights:
Figure 2 - Example of a multi-criteria decision ranking system to assess likelihood of failure.
4) Identification of the priority pipes
After the key aspects are defined (1), scores for each pipe and aspect are calculated (2), and the multi-criteria decision ranking system is defined (3), the priority pipes can be identified. Priority pipes are those represented with highest scores and by default are color coded red and represented with a high grade in the application.
Below an example of the results displayed in the map, with the identification of priority pipes at red. Results below are based on a decision ranking system specifically focused on consequence of failure (where proximity to main roads is the most relevant aspect). The user is also able drill in into the high-grade pipes to identify the exact scores and pipes ID.
Figure 3 - Results based on a decision ranking system specifically focused on consequence of failure where proximity to main roads is the most relevant aspect.