MODSEL - SELECTIVITY MANAGEMENT IN ASYCUDA++ Ó UNCTAD - SITE (V1.15) 6.15 Fig 6.5 MODSEL : Functions: Value control management: Value control formula: Update (+ Local menu) In this example the Code has been given the name “NETMASS” with the description “Calculation of unit price per kilo (netmass)”. Moving into the  ‘Formula’ text box activates the editing capabilities. Writing a formula requires an understanding of ASYCUDA++ rules syntax.  Lookup tables, for lists of acceptable keywords, variables and functions, are available through the  ‘Local menu’. See Appendix A, "Taxation Management" for further details on using Rules and Rules syntax. Descriptions of Selectivity keywords, functions and variables are in MODSEL, Selection Criteria Syntax. Apart from using the weight in the formula calculation, (e.g. ‘NetMass’), writing a valuation control formula usually means calling upon one of a number of supplementary unit variables. For example, a ComCode may have Supplementary Units, and the ‘order of appearance’ of those Supplementary  Units  may  vary  between  codes,  what  is  ‘SuppUnits’  for  one    ComCode  may  be ‘SupValue1’ or ‘SupValue2’ for another. Example: Formula “UNIT” If SuppUnits > 0 THEN Result IS StatVal / SuppUnits; Endif: The  coding  example  above  is  the  basic  formula  for  unit  value  calculation.  It  takes  the  item  level statistical value and divides by the variable, ‘SuppUnits’ . The first line names the formula as “UNIT”. The second line is for error checking, by verifying that ‘SuppUnits’   has  a  value  greater  than  zero.   ‘SuppUnits’  is  the  primary  data  element  used  for collecting  and  storage  of  quantity  details.  The  outcome  of  the  calculation  is  stored  as  a  variable called ‘Result’. Selection Criteria Using Value Controls The use of Rules to define criteria for selecting particular transactions or transactions which meet a ‘profile’ are explained in Making Selections  and in detail in Care must be taken to ensure that the variable chosen for use correctly represents the Statistical Unit attached to the Commodity Code within the Tariff file.