The questionnaires that the index is built on are activated through a phone call by a professional call center to the purchasing managers of the specified sample group, on the 20th- 21st-22nd of each month. The raw data that makes up the PUMAX index covers the responses of the workplace purchasing managers’ regarding the current month, on the basis of a scale that includes the options of “increased/decreased/has not changed”. The sample size includes 500+ companies based on a mix that represents the weight of service and industry sectors in economy.
The gleaned data is used to create the monthly sub-indices that measure different facets of the well-being of the company. Each of the sub-indices represents a dispersed value from 0 to 100 that totals up to half of those who responded “increased” and “has not changed”. For instance, if there were equal number of respondents who answered as “increased” and “decreased”, the dispersion value would be 50. This calculation is based on the percentage of those who answer “decreased” while calculating the delivery time index, to ensure that the indicators are in the same direction. Each of these sub-indices are then adjusted for working-day calendar effects which also used by the Central Bank of Turkey. A reading above 50, points at a development and positive progress in the last month, whereas a value below 50 is perceived as a negative development.