Gantt Question

Good morning.

I've done some searching through the forum and figured out how to create the Gantt chart I was looking for. I need to take it one step further, however. I want to be able to use the Gantt chart to view future year data. The chart currently displays 2008's final results. However, for certain items, the results will change by a certain percentage (not consistent across all items) in future years. For example, Item C may be in its third year for 2008, putting it at approximately 58% of its total potential production. I know that in its ninth year, 2014, it will be in full production. However, I also know that other items will be ending their production life within that time, creating gaps in overall production. I need to be able to see these gaps and plan ahead to fill them before they appear, so I need to be able to look at this Gantt chart and, given a table of production life for each item, be able to tell the Gantt chart I want to see results for 2014. Is this possible? Do I make sense?

Thanks.

Sorry. I've copied over my Gantt sheet into a new workbook, and pieces of two of my other worksheets. The 'bins' worksheet contains details by year, side, commodity, variety, and ranch location of quantities harvested each day. The 'leaf' worksheet contains details of each variety by ranch location of when the current variety was first planted/grafted, and what year they were, or will be, in any particular leaf (ie, first year after graft = first leaf). I have yet to create another table that, based on historical data for the same variety on other blocks, details the expected percentage of production that each variety will have in each leaf year (full production arrives near sixth leaf). I need not only to see the Gantt chart the way I see it now, but also to have an accompanying line chart that shows the peaks and valleys of production throughout the year so that the valleys can be filled. To do this, I need to be able to look at future production based on the leaf table and the yet to be created production percentage table. Does that make more sense?

Not really, no. Let's say I take all of my 2008 Nectarine data and put it into an Area chart for the year. I'll see all of the peaks and valleys of nectarine production throughout the 2008 season. Now, let's say I want to see what our nectarine production will be in 2014. I want to see where my valleys are, as far as which time of year has the lowest production, so that I can plan new plantings that will reach maturity by that time to fill in the gaps.

In order to get to that point, I need to know when certain ranches will reach full production based on the year they were planted. For example, in their first year, they will produce 15% of their total potential. Second year, 30%, third year, 50%, fourth year, 78%, fifth year 90%, sixth year through thirteenth year, 100%, fourteenth year, 80%, fifteenth year, 60%, sixteenth year, 40%, etc. There is a production curve that all varieties follow. The specific percentages vary from variety to variety. So for example, anything I plant next year will reach it's fourth production year, as per the "leaf" table.

I think there's a way, as I see it in my head, for this to work, but it is highly impractical. Let's say I modify my "leaf" table to have my columns be years, rather than leaf years, and place percentages in the data table of what they will produce each year. Next, I have the "bins" sheet that shows past production. If I base all of my future harvest start and end dates on my 2008 historical data, I could create a table for every future year multiplied times the appropriate year column in my "leaf" table. Unless there is a way to have a drop-down, or input cell where I can just put in the future year, and it would automatically take my 2008 historical bin data and multiply times the appropriate block percentage from the modified "leaf" table? Then the area chart can be based on the adjusted table?

Or am I making no sense again? Because I have no idea what I'm talking about at this point.