Assessing the value of information to design site investigation and construction quality assurance programs - Risk and Reliability in Geotechnical Engineering - page 519

100%

80%

60%

40%

20%

0%

0246810 12 14 16 18 20

Sampling interval/mean defective segment length

Figure 13.49 Expected percentage of defective seam length that is repaired versus sampling interval of
destructive testing for QA/QC of geoembrane liner.

programs. The intent has been to provide illustrative examples with enough detail that read-
ers can recreate the analyses, to demonstrate with actual case histories of how these tools
can benefit the practice, and to offer practical insights into the value of information.
The following important concepts have been illustrated and emphasized:

1. The value of information depends on how useful that information will be in making
decisions. The value of information is enhanced when leaving open the possibility that
decisions may change based on the information.

2. Additional information does not necessarily decrease uncertainty; uncertainty can
increase, remain unchanged, or decrease with additional information.

3. Relationships (such as correlations) between pieces of information can significantly
affect the value of the information. While assuming pieces of information are

Mean fraction of defective samples = 20%
Average length of destructive segment = 25 m
Te st cost = $100 per sample

6

4

Defective seam cost = $50 per m

2

0

Defective seam cost = $20 per m

-2

-4

0 50 100 150 200 250 300

Sampling interval (m)

Figure 13.50 Expected benefit versus destructive testing interval for QA/QC of geoembrane liner.