Life Cycle Cost Approach
The life cycle cost approach can be used to monitor levels of service received by users and the costs required to deliver these services (Fonseca et.al, 2011). Costs are compared and assessed in relation to the level of service received by users. Services are ranked in a ladder, from no service to high or improved service, based on different criteria. Each step up the service delivery ladder requires a different combination of infrastructure, management systems and human resources.
Sanitation
The sanitation service ladder is designed to describe domestic (household) sanitation (Potter et al., 2011). The service criteria for sanitation are accessibility, use, reliability and environmental protection (see table 1). The household service level is decided by the lowest level of service received on one of the four service criteria—accessibility, use, reliability and environmental protection. These criteria can vary across countries, with the basic level of service being the national norm. Typically, a higher level of service means more of every criterion. Each criterion is measured by one or more indicators. For example, the indicator for the use criterion is how many people in the household use the sanitation facility.
Table 1. Sanitation service levels
| Service Levels | Accessibility | Use | Reliability (O&M) | Environmental protection (pollution and density) |
| Improved service | Each family dwelling has one or more toilets in the compound | Facilities used by all members of the household | Regular or routine O&M (including pit emptying), requiring minimal user effort | Non-problematic environmental impact; Disposal and reuse of safe by-products |
| Basic service | Latrine with impermeable slab (household or shared) at a national norm distance from household | Facilities used by some members of household | Unreliable O&M (including pit emptying), requiring high user effort | Non-problematic environmental impact and safe disposal |
| Limited service | Platform without impermeable slab; Separated faeces from users | No use or insufficient use | No O&M (pit emptying) taking place and the presence of extremely dirty toilets | Significant environmental pollution, worsening with increased populations |
| No service | No separation between user and faeces, e.g. open defecation |
Source: Potter et al., 2011, page 21
The service levels and criteria for sanitation can be adapted for use at workplaces and in schools and colleges.
Water
A water service level characterises the benefits that users receive, measured by a combination of criteria (see table 2). The household service level is determined by the lowest level of service on any of four service criteria: quantity, quality, accessibility or reliability (Moriarty et.al, 2011). These criteria can vary across countries, with the basic level of service being the national norm. Typically, a higher level of service means more of every criterion. Each criterion is measured by one or more indicators. For example, the indicator for reliability is the number of days when water is available throughout the year.
Table 2. Water service levels
| Service levels | Quantity (litres per person per day) | Quality | Accessibility (minutes / capita / day) | Reliability |
| High | Greater than 60 | Good | Less than 10 | Very reliable |
| Intermediate | Greater than 40 | Acceptable | Less than 30 | Reliable / secure |
| Basic (normal level) | Greater than 20 | |||
| Substandard | Greater than 5 | Problematic | Less than 60 | Problematic |
| No service | Less than 5 | Unacceptable | Greater than 60 | Unreliable / insecure |
Source: Moriarty et al., 2011, page 12
The life cycle cost approach has been developed in the WASHCost project. WASHCost was led by IRC International Water and Sanitation Centre, running from 2008 to 2012, in rural and peri-urban areas of Burkina Faso, Ghana, India, and Mozambique.
Key documents
- Fonseca, C. et al., 2011. Life-cycle costs approach: costing sustainable services. (WASHCost Briefing Note 1a). The Hague, The Netherlands: IRC International Water and Sanitation Centre.
- Moriarty, P. et al., 2011. Ladders for assessing and costing water service delivery. (WASHCost Working Paper 2). 2nd ed. The Hague, The Netherlands: IRC International Water and Sanitation Centre.
- Potter, A. et al., 2011. Assessing sanitation service levels. (WASHCost Working Paper 3). 2nd ed.
The Hague, The Netherlands: IRC International Water and Sanitation Centre.