Hardware Reference
In-Depth Information
Screening Process:
Screening process is the last step in OMSD Model. It utilizes
attribute - measure matrix and a set of pre-defined decision factors in order to decide
on the optimum set of measures. The defined screening rules are implemented during
the final screening process. These rules are based on a number of factors such as the
Number of usage, Importance and Cost. A heuristics approach is used to make a
tradeoff. After every selection, a comparison is made with the constraints (cost and
time) [16] in order to control the progress. Certain tradeoffs are also needed with
respect to the importance of the measure and the cost for the measure, but these trade-
offs are primarily dependent on the organizational business needs and priorities.
The model selects at least one measure for each attribute because each attribute
represents a particular question. Order of these rules could be changed based on the
organizational requirements. Steps include in screening process are given below:
Step 1:
Select Attribute 'Ai' Where i = {1,2,3,4…..n}
Step 2:
Select each measure 'mi' which satisfy attribute 'Ai'
Ai= {m1, m2, m3…..mn}
Step 3:
Calculate the usage Umi of each measure mi
Usage of mi (Umi)=How many time it is used in Attribute-Measure
Matrix.
Step 4:
Perform Comparisons on the base of Decision factors.
•
Compare the Use of each measure mi with all selected measures
•
Compare the Importance of each measure with all selected measures
Importance = weight assigned to Measure mi (Step 4: Factor-Value)
Compare the Cost of each measure with all selected measures
Cost = Calculated through Step 4 of the Model
Step 5:
Measures are selected after step 4. Note that measure selection is
completely dependent on the organizational decision (means which decision
factor is of high importance for organization).
Step 6:
Check the selected measure against the pre-defined constraints.
Primary aim of this step is to control the measurement process in order to
make sure that cost of the selected measures remains under the cost limits.
This step is repeated at the end of each iteration during the screening process.
Step 7:
Check the following conditions:
•
•
If Cost of selected measure (Cms) is less than Constraint Cost
(Ccost) then continue from step 1
Cms < Ccost (6)
•
If Cms > Ccost terminate the process.
Step 6 and 7 are mutually exclusive. Once the selected measure is analyzed against
the defined constraints, decision about continuation or termination of measurement
process is made on the basis of condition in step 7. An optimum measure set is se-
lected after completion of these steps (either termination condition is met or all meas-
ures are gone through).
