When should a business start managing by forecast?

As you asked that WHEN SHOULD START BUSINESS MANAGING FORECAST, I would like to say, before starting any activity of business it is the forecast and assumptions that gives strength to start. 

So without forecasting business is not possible. Now for the correct point of combination of bottom up and top down meeting, in practical I would like to say its not possible to combine them, ( as per my experience), YES but they can synchronized to a degree where so streching is there. 

So synchronization point of bottom up and top down concept is the agreement of mutual benefits for management and workers to perform business activity in which

1) profits are to be maintained and can be increased, 

2) to plan the working path ways

3) to maintain harmony and coopreative atmosphere.

These are the parctical scriptures which I felt personally apart from the BOOKS WHICH I READ during my education.

I'm inclined to agree with Arinjay Dadhich.  Before entering a market, a good forecast is required and should cover the market, niche, competitors, customers, and potential growth, among other things.  In this way you can time the release of products to hit the market during the best time for you.  To do otherwise is to operate blindly.

What is the need?  Who is going to fill that need?  What is required?  Can we do it?  What do we have that our competitors don't?

There are lots of questions to ask, but it's important to have some of the answers before blindly spending money, and not getting anywhere.  It will also be helpful for forecasting personnel requirements, financing, even real estate requirements.

When should you begin to manage by forecasting?  Before you begin, once you start, and from then on.

i believe Business forecasting is very useful for businesses as it allows them to plan production, financing and so on.forecasting allows businesses to plan ahead of their needs, businesses should be managed by forcasting as you are asking in order to start raising their chances of keeping healthy through all markets.

to start managing a business by forcasting you are slaving your company's future to such forcast being right or wrong.when a business decides they want to follow such path,they must be prepared to accept the end resuilts being positive or negative.

business should start using forcasting if they want to set a reachable target within a known time frame.

totally agreed with arinjay & nishant ,,, no need to add more............

Forecasting is a tool which has to be put into practise right from the begining of any business. This is a tool which balances between inflow and outflow of resources, products. services and maintains a healthy financial status.

Forecasting has to be done scientifically and cannot be generalised on emotional assumptions or feelings as it has financial implications on the business.

Forecasting takes place (should take place) during all stages, from inception and onwards. Actually even before inception, cause a good business plan is charecterised by plenty of forecasting, nothing but forecasting. 

As to the correct combination of Bottom Up and Top Down modeling, this depends on the business size among others. For SME's, a bottom-up strategy may be more suitable. The bigger the business becomes, the more top-down strategizing takes place (regardless of whether centralization of decision making is good or bad), as decisions increasing lie with top management and the "distance to work floor" increases, when companies become bigger.

When there is a shortage of information, i.e., uncertainty is high

Forecasting is predicting the future. This is done at the Initial Stages as a part of the identification of Opportunities,Threats and for Strategic & Risk Planning before moving on to the Execution Phase of Business, Operations or Projects. The Final Business Plans are based upon taking into consideration the long term Business Opportunities, Threats & Risks affecting the survival or growth of the business.

However since it is impossible to predict the future correctly, it is required to do Forecasting at frequent intervals during the Execution Phases of the Business, Operations or Project to identify new Opportunities, Risks and plan New Strategies accordingly.  

Forecasting (like weather forecasting) is basically an attempt to predict what the future status will be based on some facts and indicators that influence that future status >> For example, sales department (function) has to do a sales forecast on regular basis for pre-defined periods (monthly, quarterly, semi-annual and annually)  even if the cannot confirm100% that this sales forecast will fully materialize .  This kind of information (based on predictive  analysis, extrapolation, what-if scenarios, .,.etc) is still helpful (as a baseline to be reviewed and updated on frequent basis).  It will help steer up the organization towards preset (expected/desired) results and take necessary actions accordinlgy. 

Agree with both answers given by Mr.:Amer & Mr.: Michael too

Good answers given by Arinjay and Khatim. I will add my two cents below..

Business Forecasting is an estimate or prediction of future developments in business such as sales, expenditures, and profits.

Forecasting has become an invaluable tool for businesspeople to anticipate economic trends and prepare themselves either to benefit from or to counteract them. If, for instance, businesspeople envision an economic downturn, they can cut back on their inventories, production quotas, and hirings. If, on the contrary, an economic boom seems probable, those same businesspeople can take necessary measures to attain the maximum benefit from it. Good business forecasts can help business owners and managers adapt to a changing economy.

Forecasting starts ahead of the fiscal year's goal setting for orgnizations, and will be reviewed periodically (quarterly, etc).