# Patent

## Title
Scenario-dependent evaluation formula

## Abstract

A method and apparatus create a way of controlling alternative values of cell contents of a data flow network. Alternative values are computed from alternative formulas, which may be turned on and off in separate layers. Typically, one formula is provided for each layer for each cell of the data flow network. Layers can be grouped together to model different scenarios and can be added or removed.

## Background
CROSS-REFERENCES TO RELATED APPLICATIONS
This application is a continuation of application Ser. No. 11/224,761, now U.S. Pat. No. 7,676,738, filed Sep. 13, 2005, which claims the benefit of U.S. Provisional Application No. 60/609,118, filed Sep. 13, 2004.


STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable.
REFERENCE TO MICROFICHE APPENDIX
Not Applicable
BACKGROUND
1. Field of the Invention
This invention relates generally to computational modeling, and, more particularly, to computer modeling of alternative financial scenarios.
2. Description of Related Art
Every business, irrespective of its age and size, must at one time or another perform financial planning as a critical activity for managing cash flow and communicating the financial health of the business. For new businesses, the preparation of financial projections is integral to the business planning process. For larger companies, financial planning forms part of annual budgeting and plays an important role in long-term planning, business appraisals, and corporate development.
Central to financial planning and analysis is the construction of complex mathematical models that can reflect finances, activities, and other business factors such as external economic and/or environmental factors. A simple model such as “Sales minus Costs equals Profits” (i.e., S−C=P, expressed as a formula) is used to derive projected profits from assumptions about future sales and costs. In practice, financial planning models are highly complex as they must accommodate multiple time periods (months, quarters, and years) and handle hundreds of variables relating to sales, costs, and other subjective business factors. When visualized as a multi-dimensional array of information (data) and computations (formulas), the volume accumulates very quickly. A very large number of variables may be required to generate a set of complex financial projections.
Common software tools that are used to manage such complex financial planning models include spreadsheet programs and proprietary accounting software tools with fixed (static) computational formulas and outputs.
Conventional financial planning models are used for many purposes, including constructing and comparing financial scenarios, performing sensitivity analyses, and comparing model results against actual results. Traditionally, in spreadsheets, this is accomplished by altering the formulas of result cells. However, if one forgets to change cells' formulas back to their original contents, the model becomes permanently altered. Sometimes, the model will be copied and then altered. However, maintaining multiple models in a consistent manner is difficult. Either way, traditional approaches can, and often do, compromise the integrity of the computation model.
BRIEF SUMMARY OF THE INVENTION
In accordance with an embodiment of the invention, software creates a way of controlling alterations to cell contents of a data flow network so they can easily be turned on and off as separate layers. These layers can then be grouped as scenarios. Scenarios allow different layers of formula changes to be easily added and removed from the model.
In accordance with one aspect of the invention, a system for providing alternative computational results in a computer-implemented model includes cells each representing a piece of data in the computational model. The system further includes formulas for each cell, which indicate alternative values of the respective cell. The system also includes layers, which group together formulas from different cells. Software is provided for selectively enabling and disabling the formulas on a layer-by-layer basis. The software operates to produce one value for each cell at a time.
In accordance with another aspect of the invention, a system provides alternative computational results in a computer-implemented model. The system includes cells each representing a piece of data in the computational model. For each cell, the system includes formulas to indicate alternative values of the respective cell. The system includes software for selectively enabling and disabling each of the formulas. The formulas for each of the cells are nested, and each formula acts upon the value of any formulas nested within it to produce a single value for each cell at a time.
In accordance with yet another aspect of the invention, a software system for providing alternative computational results in a computer-implemented financial model includes a plurality of cells, each representing a piece of financial data in a financial model. For each cell, the software system includes formulas for prescribing alternative values of the respective cell. The formulas are arranged in an ordered set for which the value of a formula occurring later in the set is computable based upon the value of a formula occurring earlier in the set. Each of the formulas is selectable for prescribing a single value for the respective cell.
In accordance with yet another aspect of the invention, software provides alternative computational results in a computer-implemented model. The software includes a plurality of cells. The software includes, for each cell, means for prescribing a plurality of alternative values for the cell and means for selecting one value from among the alternative values of the cell. The software further includes means for organizing selected alternative values into a scenario and means for providing different scenarios representing different groupings of alternative values.
In accordance with yet another aspect of the invention, a method provides alternative computational results in a computer-implemented model. The method includes prescribing, for each of a number of cells, formulas indicating alternative values of the respective cell. For each cell, the formulas are arranged in an ordered set wherein each formula has a location. Formulas are grouped together from different cells having the same locations in the respective ordered sets to form layers. The method includes selectively enabling different layers to model financial data under different scenarios.
In accordance with yet another aspect of the invention, a method provides alternative computational results in a computer-implemented model. The method includes prescribing, for each of a number of cells, formulas indicating alternative values of the respective cell. The method groups together formulas from different cells to form multiple ordered layers. Different layers are selectively enabled to model financial data under different scenarios.



BRIEF DESCRIPTION OF THE DRAWINGS
Various aspects of the invention will become apparent from a consideration of the ensuing description and drawings, in which—
FIG. 1 is a data flow diagram that shows formulas in cells of a data flow network referencing other cells, according to the prior art;
FIGS. 2-3 are data flow diagrams that show nested or layered formulas according to an embodiment of the invention;
FIG. 4 is a flowchart showing a process for modeling data according to one embodiment of the invention;
FIG. 5 is a flowchart showing a process for modeling data according to another embodiment of the invention;
FIG. 6 is a flowchart showing a process for modeling data according to yet another embodiment of the invention;
FIG. 7 is a flowchart showing a process for modeling data according to still another embodiment of the invention;
FIG. 8 is a flowchart showing a process for modeling data according to an additional embodiment of the invention; and
FIG. 9 is a flowchart showing a process for modeling data according to a further embodiment of the invention.



DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Software according to an embodiment of the invention creates a new way of controlling alterations to cell contents so they can easily be turned on and off as separate layers. These layers can then be grouped as scenarios. Scenarios allow different layers of formula changes (also referred to as “tweaks”) to be easily added and removed from the model. Model comparisons are easily made and controlled with software by keeping all formula definitions and tweaks separated and organized as layers and scenarios. Thus, no permanent changes to a model can be inadvertently made.
This software invention is based on a data flow network. A data flow network, in simple terms, examines processes (activities that transform data from one form to another, such as formulas), data stores (the holding areas for data, such as cells organized as table rows and columns), external entities (what sends data into a system or receives data from a system), and data flows (routes by which data can flow).
In a typical spreadsheet type data flow network, each cell has a formula for computing a value. Formulas may include constants, operators, functions, and non-circular references to other cells. The network of cells can be visualized as a two dimensional data flow diagram where each cell, X, is a node with inputs from other nodes and outputs to other nodes whose formulas may refer to cell X. Each cell X may have Z number of layered formulas. The diagram must be non-circular to avoid computational loops. A typical two dimension example of a data flow network can be seen in FIG. 1. In this example, cell C is the sum of cells A and B.
“Tweakable” Formulas
According to the invention, tweakable formulas provide a three-dimensional layered data flow network. Each cell may have Z number of formulas whose results may be defined by one or more formulas arranged in the same (or different) layers. Layers are created with ordered sets of formulas: (f1, f2, f3, . . . , fn } Each formula may refer to the result of a previous formula. The value of each cell is the result of a previous formula.
An example is shown in FIG. 2. In that figure cell C has two tweak formulas, the first is the sum of cells A and B (like before) and the second tweak formula adds 5 to the result. Each tweak formula in the example is represented as a nested (or layered) circle or oval.
FIG. 3 shows two important things. First, that tweak formulas can be layered or nested any number of times. Second, the outermost tweak formula shows a replacement of a value rather than an adjustment like the middle (or second) tweak formula. The outermost (or third) tweak formula is just a constant, 17, which replaces A+B or A+B+5. This example is typical of situations where one wishes to include actual results, which replace the results from the formula.
Each layer of tweak formulas may be turned on and off, which makes it possible for cells to have many different alternative results depending on which tweak formulas are on or off. In the example above, if the second tweak and third tweak are turned off, the cell will produce the original result value of A+B. However, if the second tweak formula is turned on then the result value is A+B+5, or if the third tweak is turned on then the result value will be 17.
Layers
As previously mentioned, tweaks must be ordered so that only one value can be computed. The ordering can be accomplished in any number of ways. In projected financials, we use layers. Other systems might use alternative ordering mechanisms. In projected financials, layers are also used to indicate which tweaks are turned on or off.
When a layer is turned off, then all tweaks in that layer are turned off. This allows the user to use layers to represent various events in natural ways.
For example, an event “expenses are 8% higher” can be described as a set of tweaks, one for each cell representing an expense, that multiplies the previous result by 1.08. If this layer is turned on, then all expense cells will be 8% higher, and if turned off, the expenses are unchanged. A second layer, called “New Computer,” might be used to represent the purchase of a new computer in the month of June. It would consist of a set of tweak formulas that would express all the information related to the purchase, including such things as depreciation, accounts payable, etc.
Scenarios
Layers can be combined in arbitrary ways to create different scenarios. For example, scenario A might turn on higher expenses and “New Computer” whereas scenario B might turn both of them off. Note that turning layers on or off does not change the underlying model, only how the numbers are computed. Using tweaks and layers will preserve the integrity of the model because instead of altering the model, a new layer is “wrapped” around the model, and this layer can be easily turned on or off as needed.
The software according to the invention allows model results and actual results to co-exist in the same context (i.e. data flow network), and ensures that actual results flow smoothly into model results. This software can be used for many purposes, including, but not limited to, constructing and comparing financial scenarios, performing sensitivity analysis, and comparing model results against actual results.
As used throughout this document, the words “comprising,” “including,” and “having” are intended to set forth certain items, steps, elements, or aspects of something in an open-ended fashion. Unless a specific statement is made to the contrary, these words do not indicate a closed list to which additional things cannot be added.
Having described one embodiment, numerous alternative embodiments or variations can be made. Those skilled in the art will therefore understand that various changes in form and detail may be made to the embodiments disclosed herein without departing from the scope of the invention hereof

## Claims

1. A machine implemented with a computer programmed for executing a computational model, the machine comprising:
a plurality of computer-implemented cells each representing a piece of data in the computational model;
for each cell, a plurality of computer-implemented formulas indicating alternative values of the respective cell, wherein the plurality of formulas for the plurality of cells are grouped in layers wherein each layer includes one formula for each of the plurality of cells and each layer can be enabled or disabled; and
a data processor configured for computing values for the plurality of cells for one enabled layer based on values computed for at least one other enabled layer,
wherein, for each of the plurality of cells, the plurality of formulas is arranged in an ordered set wherein each formula has a location, and
wherein each layer groups together formulas from different cells having the same location in the ordered set.

2. The machine as recited in claim 1, wherein the data processor is configured for computing a first set of values for a first enabled layer and computing a second set of values for a second enabled layer, wherein the second set of values depends upon the first set of values.

3. The machine as recited in claim 1, further comprising a plurality of scenarios under which the computational model can be run, wherein each scenario comprises at least one enabled layer.

4. The machine as recited in claim 3, wherein each scenario comprises a plurality of enabled layers.

5. The machine as recited in claim 1, wherein the plurality of formulas for the plurality of cells each includes at least one of a function, a constant, an operator, and a non-circular reference to another cell.

6. The machine as recited in claim 1, wherein formulas in one layer are arranged to computationally model a financial characteristic, and formulas in another layer indicate actual financial information for the financial characteristic.

7. The machine as recited in claim 1, wherein different layers specify alternative sets of values that can be plugged into the computational model.

8. A computer programmed with software for implementing a special-purpose machine for executing a computer-implemented model, comprising:
a plurality of cells each representing a factor in the computer-implemented model; and
for each cell, a plurality of formulas indicating alternative values of the factor represented by the respective cell;
wherein the plurality of formulas for each of the plurality of cells are nested,
wherein each formula acts upon the value(s) of one or more formulas nested within it to produce a single value for each of the plurality of cells at a time, and
wherein, for each of the plurality of cells, the plurality of formulas are arranged in an ordered set wherein each formula has a location,
the method further comprising a plurality of layers, wherein each layer groups together formulas for different cells having the same location in the respective ordered sets.

9. The computer as recited in claim 8, wherein different layers of the plurality of layers corresponds to different circumstances to be modeled.

10. The computer as recited in claim 8, wherein the formulas in at least one layer of the computer-implemented model correspond to actual business results.

11. The computer as recited in claim 8, wherein the computer-implemented model is a financial model and the factors are business factors.

12. A method for providing alternative computational results in a computer-implemented financial model, comprising:
providing a plurality of cells;
for each cell, providing a plurality of formulas arranged in an ordered set wherein each formula has a location;
arranging the plurality of formulas for the plurality of cells in a plurality of layers, wherein each layer groups together formulas having the same location in the respective ordered sets; and
executing the computer-implemented financial model on a computer, including computing values for formulas occurring later in each ordered set based upon values resulting from formulas occurring earlier in the respective ordered set.

13. The method as recited in claim 12, further comprising selectively enabling and/or disabling formulas for the plurality of cells on a layer-by-layer basis, wherein the step of executing computes values for formulas in enabled layers and does not compute values for formulas in disabled layers.

14. The method as recited in claim 13, further comprising a plurality of scenarios under which the financial model can be run, wherein each scenario comprises at least one enabled layer.

15. The method as recited in claim 14, further comprising:
creating a first scenario that indicates forecasted performance;
creating a second scenario that indicates actual performance;
executing the computer-implemented financial model with the first scenario and with the second scenario to provide first and second results, respectively; and
comparing the results of the first scenario with the results of the second scenario.

16. The method as recited in claim 14, further comprising:
providing different scenarios that have different values for at least one financial characteristic; and
comparing results from the different scenarios to ascertain a sensitivity of the results to variations in the at least one financial characteristic.