Determine the indicator's value by using the following methodology:
1) Define a limited number (2 - 6) of the most important (types of) products that you would like the sellers to sell (e.g. poultry vaccines in small doses, disinfectants for chicken coops, etc.).
2) For each of the most important (types of) product, define the minimum amount the seller should have in stock (e.g. at least 5 sachets of tomato seeds). There is no fixed methodology for determining the minimum amount – it is only used to avoid a situation when even a shop that has extremely low stock is considered as having an adequate supply of the required products. At the same time, be realistic – many sellers cannot take the risk of stocking very large volumes (due to limited capital, insufficient space, concerns about expiry dates, fear of theft, etc.), so do not set these targets too high.
3) Decide whether in order to meet the indicator, the sellers need to have all the (types of) products in stock or whether you can accept that a small portion of the assessed (types of) products (e.g. 30%) are not available in the required quantity. This is recommended especially if you assess a larger number of products as it might not be fair to conclude that a seller does not stock enough products if only a few out of many products are missing. As much as possible, pilot this survey to understand whether your expectations are realistic (if not, revise them).
4) Conduct an assessment among all (or a representative sample of) the target sellers enquiring whether they sell the target products and if so, whether they are available in the desired quantity (consider using a well-structured checklist). Do not inform the sellers in advance about the data collector’s visit.
5) Count the number of sellers offering the minimum amount of the desired products (as defined in point 3).
6) If there are likely to be significant fluctuations in the availability of the desired product, repeat steps 4 and 5 a few weeks / months later (depending on when people need the products / when the products should be available).
7) To calculate the indicator's value, divide the number of sellers offering the minimum amount of the desired products by the total number of surveyed sellers. Multiply the result by 100 to convert it to a percentage.