How does a restaurant predict the demand of each item in the menu, so that the food isn't wasted?

we need to ask the customer first what they want to eat,what kind of restaurant we have like that and then we suggest the best and specialty.and we need to explain what kind of food like that .ex.if the customer want something spicy diahes we should suggest the spicy food.or if they want something grilled we can suggest the grilled.we must know first the customers likes and dislike.

Menu Engineering every6 months, keep the top10 dishes from each category, revamp the remaining choices.

FOOD QUALITY AND GOOD SERVICE

in order to predict the demand of each item that will not be wasted first & foremost we should a make a forecasting with regard to the budgeting of food items,secondly you should an itinerary about the menu that u will gonna serve to your guest...food is the most important thing in life because its give high power demand for our needs and wants.with it come to food people are critics they choose   the good quality  of each food that they will gonna buy.

If the restaurant just started its operation, its hard to predict or forecast the volume of food to prepare. The precarious situation will takes months to keep on tracking  the moving and the unmoving items in the menu. Once that some of the items are constantly moving and some are not it needs menu engineering for those unmoving until100% moving. Then it would be the right time to forecast the volume of raw food of each menu ( holidays seasons or celebration is  considered in forecasting). Adjustment is somehow happen until to reach the right forecasting of the volume  of food to prepare.

you can use a menu mix weekly/monthly basics to keep track of your most selling dishes in the rest.