well.. i think with the help of REVIT software, which is a BIM interfaced software we can easily Estimate the minute quantity also.. which is easier and also has a good user interface.
BIM might mean quantity surveying processes would change, it doesn't change how the profession is practiced. There could be divided opinions about this, regardless the truth is that BIM provides more opportunities for quantity surveyors to improve their outcomes. QS who are not BIM compliant are likely to diminish in value and relevance within the next decade. Those who are well rooted in BIM will be better for it.
As Yeshwanth and Oluwole already said, the point I would like to add here is that there are currently a number of QS software such as CATO Cost & Programme Management software, PlanSwift’s estimation software linked with BIM-based software which could help to improve QS productivity, reducing errors and centralisation of cost data.
By parametric associativity of BIM, quantity surveying and design processes are better synchronized directly. For instance, changes made in a BIM drawing are automatically reflected or updated in the associated priced and unpriced bill of quantities, and vice versa.
Quantity surveying is a part that can be extracted from a BIM e.g you can extract quantity from Revit into excel format. you can also use some quantity surveying software which is compatible with your BIM software which you are using. However, in my practical experience, BIM will not give you the quantity of certain materials like paint etc. directly. May the new version of modeling software can do it. This you may have to check.
Actually, cost estimation and quantity surveying (quantity takeoff - QTO) are shifting to parametric QTO. A cost estimator will ask: What happens, if we use another product within the given constraints? The conventional method will reextract all data. A more sophisticated software / method will extract and link constrained parameters, too (I'm not aware of any). An estimator can "play" with the parameters and can estimate the impact. Excel is not a sophisticated method. Indeed, cost estimation is a semantic modeling task. A cost estimator will group qualities and work units and will associate them with 3D components. Any finish (i.e. paint) is associated to a 3D space which is surrounded by constructive components. Therefore, information of quantity has to be derived by a geometry kernel with the help geometrical processing.
Revit can give you quantities in the specific format required if you tailor the material takeoff sheets according to your needs. For example, by default the volume for concrete is given in CF in Revit, but you can change this to CY. This rule applies to painting and other materials, too. Also, for the comparison between products, different versions of the Revit model can be created, but it is still needed to export them to excel or some other platform to combine QTOs with cost data and finally compare costs for both versions. That is one of the ways to play with design alternatives with BIM.
You are right. Revit is one way. There are similiar solutions. The question is, can it be recommended. This implies the question, how efficient and detailed a QTO can be done from a model and whether this model exists or not. In practice, a lot of work is spent in enhancing an existing model or generating a new model. If a company has to create a new model for QTO or bidding only, there a custom threshold up to that modeling does not make a sense. Anyway, such a "special" model has difficulties in reuse since it is made for one purpose. Selling such a model and its QTO might be a business case. In my opionion, no quantity surveyer (in germany) asks himself/herself whether to move towards BIM - only when.
Here is a link to a publication which tries to summarise some benefits.
http://www.sciencedirect.com/science/article/pii/S0263786312001779
You are right about the modeling part, as it will take time to have a complete or specific model ready for QTO and also, the company will need employees who can work with Revit extensively. For the projects that already has a Revit model, I would recommend QTO with Revit. However, one problem is to have a "correct" model. I think this is the part to consider when moving to BIM takeoff. QTO will be only as good and detailed as the model is.
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