DESCRIPTION
FIELD OF THE INVENTION
In the field of intellectual property portfolio cost optimization, a method is disclosed to optimize maintenance cost of a patent portfolio.
DEFINITIONS
Productive Patent: Productive patent is a patent which is considered to have economical, legal, or technical importance for assignee of the patent, either at present or in future.
Non-productive Patent: Non-productive patent is a patent which is not considered to have economical, legal, or technical importance for assignee of the patent, either at present or in future.
Patent Portfolio: Patent portfolio is a collection of patents belonging to an assignee.
Term of a Patent: Term of a patent is the number of years for which the patent can be maintained in force. At USPTO, for example, term of a patent is 20 years.
Age of a Patent: Age of a patent is the time elapsed since grant of the patent.
Maintenance Fee: Maintenance fee is a fee which is to be paid to a patent office to maintain a granted patent in force. At USPTO, for example, first maintenance fee of USD 900.00, second maintenance fee of USD 2,300.00 and third maintenance fee of USD 3,800.00 is to be paid after 3.5 years, 7.5 years and 11.5 years of grant of the patent, respectively.
Maintenance Fee Age: Maintenance fee age is the age of a patent at which payment of maintenance fee is required by a patent office. At USPTO, for example, first maintenance fee age is 3.5 years; second maintenance fee age is 7.5 years and tiTird maintenance fee age is 11.5 years.

Phase of a Patent: Phase of a patent is defined with respect to maintenance fee age of the patent. Phase of a patent is 1 when the age of the patent is less than the first maintenance fee age; phase of a patent is 2 when the age of the patent is between the first maintenance fee age and the second maintenance fee age; phase of a patent is 3 when the age of the patent is between the second maintenance fee age and the third maintenance fee age; and so on. For patents at USPTO, for example, phase of a patent of age 2 years is 1; phase of a patent of age 6 years is 2; phase of a patent of age 10 years is 3; and phase of a patent of age 15 years is 4.
Class of a Patent: A class of a patent is a category in a hierarchical classification of patents, whereby the hierarchical classification of patents is defined by a user.
Sub-class of a Patent: A subclass of a patent is a category in a hierarchical classification of patents which is just one level higher to the patent in the hierarchical classification, whereby the hierarchical classification of patents is defined by a user.
Market Growth of a class of a patent: Market growth of a class of a patent is percentage change in revenue generated by the class of the patent over a period of time.
Value of a Class of a Patent: Value of a class of a patent is the amount of money that is considered to be a fair equivalent for the class of the patent.
Discount Rate of Value of a Class of a Patent: Discount rate of value of a class of a patent is percentage change in the value of the class of the patent over a period of time.
Patent Information: Patent information is information about a patent. Patent information includes, but is not limited to, patent number of a patent, term of the patent, phase of the patent, age of the patent, classification of the patent, number of foHA/ard citations of the patent, date of publication of forward citations of the patent, sum of all forward citations of patents belonging to sub-class of the patent, number of patents in sub-class of the patent, number of patents in class of the patent, market growth of the class of the patent and discount rate of value of the class of the patent.
Strength Index: Strength index of a patent is an index of the strength of the patent relative to other patents of the patent portfolio. The strength of the patent may

be with respect to, but not limiting to, one or more of tlie broadness of tlie claims, the geographical domain of the patent and licensing potential of the patent.
Cost Index: Cost index of a patent is an index of expected profit from the patent relative to other patents of the class of the patent.
Patent Office: Patent office is a government body that studies claims for, grants, and maintains records of patents in a country.
BACKGROUND
Intellectual property is an important asset for organizations accounting for a considerable portion of an organization's net worth. Patents owned by an organization form a major part of the organization's intellectual property. Patents granted by a patent office are maintained in force by payment of maintenance fee to the patent office at certain time intervals. Different patent offices have different regulations for payment of maintenance fee. USPTO, for example, requires payment of patent maintenance fee of USD 900.00, USD 2,300.00 and USD 3,800.00 after 3.5 years, 7.5 years and 11.5 years of grant of the patent, respectively.
The number of patents in a patent portfolio affects total maintenance fee which an assignee pays for maintaining its patent portfolio. Larger the number of patents, larger is the maintenance fee. For example, third maintenance fee for 100 patents from a patent portfolio of 1000 patents in USPTO alone amounts to USD 380,000.00. The cost gets further escalated in scenarios when a patent is granted in more than one geography - as the maintenance fee has to be paid for each of the geography. Ideally the maintenance fee payable for a patent should not exceed the benefits received from holding the patent. Thus monitoring of the patent portfolio is required to ensure that fee is paid only for the productive patents and the non-productive patents are discarded.
Thus there is a need for a method of monitoring a patent portfolio and identifying non-productive patents for which assignee may stop paying the maintenance fee.

BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram illustrating an environment in which the invention works, in accordance with an embodiment of the invention;
FIG. 2 is a block diagram depicting a hierarchical structure of patents in a patent portfolio according to an embodiment of the invention;
FIG. 3 is a flow chart illustrating a method of identifying non-productive patents in a patent portfolio according to an embodiment of the invention;
FIGS. 4A-4H are block diagrams depicting graphical illustrations of output from processing module 108 as displayed on display module 110 according to an embodiment of the invention.
FIG. 5 is a flow chart representing a method of eliminating productive patents from a patent portfolio and identifying non-productive patents according to an embodiment of the invention; and
FIG. 6 is a flow chart representing a method of receiving and storing patent information of a new patent according to an embodiment of the invention.
DETAILED DESCRIPTION
In the following description, specific details are set forth in order to provide a thorough understanding of the invention. However, it will be apparent to a person ordinarily skilled in the art, that the invention may be practiced without these specific details. Various aspects and features of example embodiments of the invention are described in detail hereinafter.
FIG. 1 is a block diagram illustrating an environment in which the invention works, in accordance with an embodiment of the invention.
The environment comprises control module 100, user 102, input module 104, database 106, processing module 108 and display module 110.
The environment of the invention comprises control module 100 configured for receiving input from user 102 via input module 104. Control module 100 is capable of storing data in and retrieving data from database 106. Examples of control module

00 include, but are not limited to, computer processing units, microprocessors and grapiiics processing units. For example control module 100 may be an Intel® Pentium® 4 Processor E5200.
Input module 104 is configured for adding, editing and deleting data in database 106 via control module 100. User 102 may send commands and inputs to control module 100 via input module 104. Examples of input module 104 include, but are not limited to, keyboards, computer mice and joysticks. For example input module 104 may be a Logitech® G15 keyboard.
Database is configured for storing patent information and mathematical equations. Examples of database 106 include, but are not limited to, disk drive, flash memory, random access memory (RAM) and magnetic disk. For example database 106 may be a model number HD153UI hard disk manufactured by Samsung®.
Processing module 108 is configured for receiving data from control module 100 along with one or more arithmetic and logical operations to be performed on the data. Examples of processing module 108 include, but are not limited to, computer processing units, microprocessors and graphics processing units. For example processing module 108 may be an Intel® Core™ 17-940 processor. Processing module 108 is configured for performing the one or more arithmetic and logical operations on the data to obtain an output.
Display module is configured for receiving the output from control module 100 and displaying the output to user 102. Examples of display module 110 include, but are not limited to, visual display units, televisions and mobile phone screens. For example display module 110 may be a Samsung® P63F 160cm plasma display.
FIG. 2 is a block diagram depicting a hierarchical structure of patents in a patent portfolio according to an embodiment of the invention.
According to an embodiment of the invention, patents in patent portfolio 200 are classified hierarchically and stored in database 106 for identification of non-productive patents.
According to an embodiment of the invention, the patents in the patent portfolio are classified hierarchically into two or more levels of classes and subclasses. The classes comprise first level of the hierarchical structure of the patent portfolio. The

classes may be created based on the products in which the patents in patent portfolio 200 are utilized, a product class, and the technology to which the patent in patent portfolio 200 belongs, a technology class. As an example, patent portfolio 200 may comprise patents related to laptops and networking. Therefore, patent portfolio 200 may comprise two classes viz. laptops 202, the product class, and networking 204, the technology class.
Each class may comprise one or more subclasses. The subclasses are created based on at least the product division of the product class and the technological division of the technology class. For example, class laptops 202 may comprise subclass bus 206, as bus is a product division of laptops; and class networking 204 may comprise subclasses networking applications 208 and wireless technologies 210, as network applications and wireless technologies are technological divisions of networking. Bus 206 is created as a subclass of laptops 202 as bus is a product division of laptops and further, patents belonging to bus may be present in patent portfolio 200.
As illustrated in FIG. 2, each of the subclasses may further comprise subclasses. For example, subclass bus 206 may comprise subclasses bus operation 212 and bus type 214; subclass bus type 214 may comprise subclass IDE 216; and. subclass networking applications 208 may comprise subclass remote administration 218. Thus, the second and subsequent levels of the hierarchical structure are comprised of the subclasses.
Each subclass may comprise one or more patents. The patents in patent portfolio 200 are at the end of a branch in the hierarchical structure. For example, subclass bus operation 212 may comprise patent P1 220; subclass IDE 216 may comprise patents P2 222 and P3 224; subclass networking applications 208 may comprise patent P4 226; subclass remote administration 218 may comprise patents P5 228, P6 230 and P7 232; and subclass wireless technology 210 may comprise patent P8 234. PI 220 is classified under bus operation 212 as PI 220 may be utilized in bus operation 212. The numbers in parentheses in FIG. 2 depicts the number of patents belonging to the corresponding patent portfolio, class, or subclass. For

example, patent portfolio 200 may comprise eight patents, class networking 204 may comprise five patents, and subclass bus 206 may comprise three patents.
According to an embodiment of the invention, class of a patent is the class under which the patent lies in the hierarchy. For example, class of patents P1 220, P2 222 and P3 224 is laptops 202; and class of patents P4 226, P5 228, P6 230, P7 232 and P8 234 is networking 204.
According to an embodiment of the invention, subclass of a patent is the subclass that is just one level higher to the patent in the hierarchy. For instance, subclass of patent P1 220 is bus operation 212; subclass of patents P2 222 and P3 224 is IDE 216; subclass of patent P4 226 is networking applications 208; subclass of patents P5 228, P6 230 and P7 232 is remote administration 218; and subclass of patent P8 234 is wireless technology 210.
FIG. 3 is a flow chart illustrating a method of identifying non-productive patents in a patent portfolio according to an embodiment of the invention.
According to an embodiment of the invention, the method of identifying non¬productive patents in the patent portfolio is described. Patents are selected from a first class of the patent portfolio to create a first non-productive patent list. Productive patents are then identified in the first non-productive list using a strength index and are removed to create a second non-productive patent list. Further, productive patents are identified from the second non-productive patent list using a cost index and are removed to create a third non-productive patent list. The third non-productive patent list represents a list of non-productive patents in the first class of the patent portfolio. The step by step method of creating the first, second and third non-productive patent list will be now elaborated with help of examples. It will be apparent to a person skilled in the art that the number non-productive patent lists which are created may vary without deviating from the scope of the invention.
At step 300, patent information for each patent of a patent portfolio is stored in database 106. According to another embodiment of the invention, the patent information of a new patent which is not present in the patent portfolio, is received from user 102 via input module 104 and stored in database 106. The process of

receiving and storing the patent information for tine new patent is elaborated in conjunction witli FIG. 6.
The patent information for a patent includes, but is not limited to, one or more of the following: patent number of the patent, term of the patent, phase of the patent, age of the patent, classification of the patent, number of forward citations of the patent, date of publication of forward citations of the patent, sum of all forward citations of patents belonging to sub-class of the patent, number of patents in sub-class of the patent, number of patents in class of the patent, market growth of the class of the patent and discount rate of value of the class of the patent.
The market growth of a class of a patent is percentage change in revenue generated by the class of the patent over a period of time. The market growth of a class of a patent may be expected year-on-year percentage change in revenue generated by the class of the patent. For example, in case, revenue generated from networking 204 was USD 10 million in the year 2008 and is estimated to be USD 11 million in the year 2009, then the market growth of networking 204 of the patent is 10%.
The discount rate of value of a class of a patent is percentage change in the value of the class of the patent over a period of time. The discount rate of value of the class of the patent may be expected year-on-year percentage change in value of the class of the patent. For example, in case, estimated value of networking 204 in the year 2005 was USD 200 million and estimated value of networking 204 in the year 2015 is USD 60 million, then discount rate of value of networking 204 is USD 14 million. Value of the class of the patent may be estimated by using various methods available in the art viz. transaction comparison method, relief from royalty method, residual income method and discounted cash flow. It will be apparent to a person skilled in the art that any other method of estimation of value may be utilized for calculating the value of the class of the patent without deviating from the scope of the invention.
At step 302, a first class of the patent portfolio is selected by user 102 and inputted via input module 104. For example, the first class selected may be networking 204, and two hundred and eighty patents out of one thousand patents in the patent

portfolio may belong to networking 204. At step 304, a first non-productive patent list is determined from the first class by processing module 108 based on the patent information stored in database 106 and a first condition. The first non-productive patent list is the list of patents from which non-productive patents are to be identified.
The first condition is criteria used for short listing the patents in the patent portfolio for the first non-productive patent list to eliminate the productive patents and identify the non-productive patents. In some embodiments of the invention, the first condition may be retrieved by control module 100 from database 106. In some embodiments of the invention, the first condition may be received from user 102 via input module 104.
User 102 may include or exclude patents in the first non-productive patent list based on the first condition. The first condition includes, but is not limited to, one or more of the following: a time factor, a list of patent numbers and one or more elimination parameters.
The time factor is a time period inputted by user 102 via input module 104. According to another embodiment of the invention, the time factor may be retrieved from database 106. The patents for which the time remaining for payment of the next maintenance fee is less than the time factor are included in the first non-productive, patent list. For example, in case the time factor is six months, then, all the patents in the first class of the patent portfolio whose next maintenance fee is to be paid within the next six months will be short listed to create the first non-productive patent list. User 102 may use the time factor as the first condition for Identification of the non¬productive patents from the patents for which the maintenance fee is to be paid in near future.
The list of patent numbers comprises the patents inputted by user 102 which are to be included in the first non-productive patent list. For example, in case, user 102 wants to include patents whose age is more than 10 years in the first non¬productive patent list, then user 102 may input the list of patent numbers comprising all the patens which are more than 10 years old.
User 102 may include or exclude patents in the first non-productive patent list based on the elimination parameters. The elimination parameters include, but are not

limited to, one or more of the following: number of patents required in the third non¬productive patent list, maintenance fee of each patent, budgetary constraints and patent geography. For example, user 102 may want to abandon 10 patents and therefore may input the number of patents required to be 10 in the third non¬productive patent list as the elimination parameter.
The maintenance fee of each patent may be used as the elimination parameter by user 102 to set a lower limit for the maintenance fee that may be paid per patent. For example, in case the maintenance fee of each patent is USD 1000, then all the patents in the first class of the patent portfolio with maintenance fee higher than USD 1000 will be included in the first non-productive patent list for identification of the non¬productive patents.
The budgetary constraints include, but are not limited to, one or more of the following: total maintenance fee payable and total maintenance fee savabie. The total maintenance fee payable is the total maintenance fee which has to be paid to maintain a granted patent in force for the remaining term of the patent. For example, in case user 102 has a budgetary constraint of USD 20,000 for the total maintenance fee payable, then the productive patents with the total maintenance fee payable of USD 20,000 are not included in the first non-productive patent list. The total maintenance fee savabie is the total maintenance fee which has to be saved by not maintaining a granted patent in force. For example, in case user 102 has a budgetary constraint of USD 10,000 for the total maintenance fee savabie, then the non-productive patents with USD 10,000 as the total maintenance fee savabie are included in the first non¬productive patent list.
Patent geography may be used by user 102 as an elimination parameter to identify non-productive patents belonging to a geography. Patents belonging to the geography inputted by user 102 are included in the first non-productive patent list. For example, based on the patent information about patent numbers and a first condition of having patent geography as USA, two hundred and forty patents with patent geography as USA may be included in the first non-productive patent list out of two hundred and eighty patents in networking 204 of the patent portfolio.

At step 306, a strength index is calculated for each patent in the first non¬productive patent list using the patent information stored in database 106. The strength index of a patent is an index of the strength of the patent relative to other patents of the patent portfolio. The strength index, for example, can be calculated by using equations 1 and 2:
Sp = y (vi'i X t?/')... (Equation 1 •
i
whereby, Vw, = !...• Equation 2)
wherein,
P is a patent;
1» is the strength index of 'p';
i is a parameter of the strength of 'p'; M"t is weight of the i*"1 parameter; and
'1\ is value of i'1 parameter for p.
In an embodiment of the invention the parameters of the strength of a patent in equation 1, may include, but not limited to number of independent claims, length of first claim and age of the patent. For example, the number of independent claims of the patent may be 2, the length of first claim of the patent may be 150 words and the age of the patent may be 8 years. In equation 1, weight of the parameters of the strength of the patent belonging to a class may be allocated by user 102 using Analytic Hierarchy Process (AHP). Further, in equation 1, value of the parameters for the patent may be allocated by user 102 on a scale of 1 to 10.
According to an embodiment of the invention, weight of a parameter of the strength of a patent in equation 1 is allocated by processing module 108 using AHP.
According to another embodiment of the invention, value of a parameter of the strength of a patent in equation 1 is allocated by processing module 108 on a scale of ItolO.
An exemplary calculation of the strength index based on equations 1 and 2 is depicted in Table 1.


The above example is only explanatory and not limiting to the calculation of the strength index. It will be apparent to a person skilled in the art that any other mathematical formula comprising a plurality of parameters, weight allocation method, scale for allocating value of patents and the likes, other than equation 1, may be utilized for calculating the strength index of a patent without deviating from the scope of the invention.
The strength index calculated at step 306 gives the productivity of a patent. A patent having higher strength index is more productive than a patent having lower strength index. A second non-productive patent list is created at step 308 by eliminating one or more patents from the first non-productive patent list based on the strength index. Therefore, the second non-productive patent list may comprise lesser number of productive patents than the first non-productive patent list. The one or more patents eliminated at step 308 are more productive based on the strength index than the patents which are not eliminated. For example, patents with the strength index above 4.50 may be eliminated and the second non-productive patent list may comprise one hundred and eighty patents whereas the first non-productive patent list had two hundred and forty patents.
At step 310, a cost index is calculated for each patent in the second non¬productive patent list using the patent information stored in database 106. The cost

index of a patent is an index of expected profit from tine patent relative to other patents of the same class of the patent portfolio.
According to an embodiment of the invention, the cost index is calculated by using equation 3:

wherein,
P is a patent;
1<1 is the subclass of 'p';
1 is the class of 'p';
1h is the cost index of 'p';
Psc is the number of patents in 'sc';
Pc is the number of patents in 'c';
/<1p is the number of forward citations of 'p';
fcsc is the number of forward citations of all the patents in 'sc';
/ is the current phase of 'p';
" is the maximum number of phases of 'p'; / is an integer between 'j' and 'n';

The value of variables in equation 3 is predetermined and stored in database 106 as the patent information. Value of the class of the patent may be determined by using various methods available in the art viz. transaction comparison method, relief from royalty method, residual income method and discounted cash flow. It will be apparent to a person skilled in the art that any other method of estimation of value may be utilized for calculating the value of the class of the patent without deviating from the scope of the invention. The value of the variables in equation 3 is pre-stored

in database 106 as the patent information and is now retrieved for calculating the cost index.
An exemplary calculation of the cost index using equation 3 is depicted in Table 2 for three patents - A, B and C.

wherein,
P is a patent;
1<1 is the subclass of 'p';
1 is the class of 'p';
1h is the cost index of 'p';
Psc is the number of patents in 'sc';
Pc is the number of patents in 'c';
/1p is the number of forward citations of 'p';

fcsc is the number of forward citations of all the patents in 'so';
/ is the current phase of 'p';
" is the maximum number of phases of 'p'; /■ is an integer between 'j' and 'n';
1di is the market growth of 'c' during i"1 phase; and
'"/E is the maintenance fee of 'p' during i phase.
The value of variables in equation 4 is predetermined and stored in database 106 as the patent information. The value of the variables in equation 4 is retrieved from database 106 for calculating the cost index.
The cost index calculated at step 310 gives the productivity of a patent. A patent having higher cost index is more productive than a patent having lower cost index. The third non-productive patent list is created at step 312 by eliminating one or more patents from the second non-productive patent list based on the cost index. The one or more patents eliminated at step 312 are more productive than the patents which are not eliminated. The third non-productive patent list may comprise lesser number of productive patents than the second non-productive patent list. For example, patents with the cost index above 1000 may be eliminated and the third non¬productive patent list may comprise ninety patents with thirty patents each in first, second and third phase, whereas the second patent list had one hundred and eighty patents.
At step 314, the third non-productive patent list is displayed to user 102 on display module 110. The third non-productive patent list represents a list of non¬productive patents in the first class of the patent portfolio.
According to an embodiment of the invention, a list of non-productive patents of each class of the patent portfolio is created by repeating steps 304 to 314. The list of non-productive patents for each class is stored in database 106. Thereafter, a collection of all the lists of non-productive patents gives a list of non-productive patents in the patent portfolio. Further, the list of all the non-productive patents in the patent portfolio is displayed to user 102. For example, three classes of a patent portfolio with ninety non-productive patents in each, gives a total of two hundred and

seventy non-productive patents in tine patent portfolio. Table 3 depicts exemplary cost
savings by abandoning the two hundred and seventy non-productive patents from the
patent portfolio at USPTO. At USPTO, for example, the first maintenance fee of USD
900, the second maintenance fee of USD 2,300 and the third maintenance fee of USD
3,800, is to be paid after 3.5 years, 7.5 years and 11.5 years of grant of the patent,
respectively.
Table 3: Exemplary cost saving by abandoning non-productive patents
I I I Maintenance fee savable
Number of non- Maintenance fee payable per
Current by abandoning non-
productive non-productive patent (in
Phase productive patents (in
patents USD)
USD)
1 90 900 + 2300 + 3800 = 7000 7000*90 = 630,000
2 901 2300 + 3800 = 6100 6100*90 = 549000
3 90 3800 3800*90 = 342000
Total Saving = 630,000 + 549,000 + 342,000 = 1,521,000
FIGS. 4A-4H are block diagrams depicting graphical illustrations of output from processing module 108 as displayed on display module 110 according to an embodiment of the invention.
According to an embodiment of the invention, patent portfolio 400 is displayed to user 102 on display module 110. When user 102 clicks command box 402 to input the first class for which patents are to be analyzed then input box 404 appears for inputting the first class. Input box 404 depicts input from user 102 as Semiconductors.
First class of patent portfolio 406 is displayed to user 102 on display module 110 according to an embodiment of the invention. When user 102 clicks command box 408 to input the patent geographies for which patents are to be analyzed then input box 410 appears for inputting the geographies. Input box 410 depicts input from user 102 as US, Japan, India, France.
First non-productive patent list 412 is displayed to user 102 on display module 110 according to an embodiment of the invention. Command box 414 is also displayed to user 102 to send command to control module 100 to calculate the strength index of

the patents in first non-productive patent list 412. When user 102 clicks command box 414 then FIG. 4D is displayed to user 102 according to an embodiment of the invention.
According to an embodiment of the invention, first non-productive patent list 416 with the strength index, sorted in ascending order of the strength index, is displayed to user 102 on display module 110. First non-productive patent list 416 is sorted by clicks command box 418 to sort the patents in ascending order of the strength index. When user 102 clicks command box 420 to input the strength index above which the patents are to be eliminated then input box 422 appears for inputting the strength index. Input box 422 depicts input from user 102 as 700.
Thereafter, second non-productive patent list 424 is displayed to user 102 on display module 110, according to an embodiment of the invention. Command box 426 is also displayed to user 102 to send command to control module 100 to calculate the cost index for the patents in second non-productive patent list 424. When user 102 clicks command box 426 then FIG. 4F is displayed to user 102.
According to an embodiment of the invention, second non-productive patent list 428 with the cost index, sorted in ascending order of the cost index, is displayed to user 102 on display module 110. Second non-productive patent list 428 is sorted by clicking command box 430 to sort patents in ascending order of the cost index. When user 102 clicks command box 432 to input the cost index above which the patents are to be eliminated then input box 434 appears for inputting the cost index. Input box 434 depicts input from user 102 as -1000.
FIG. 4G depicts display of third non-productive patent list 436 to user 102 on display module 110 according to an embodiment of the invention. Command box 438 is also displayed to user 102 to input a second class for which patents are to be analyzed. Input box 440 for inputting the second class is displayed when command box 438 is clicked by user 102. Command box 442 is also displayed to user 102 to show all the non-productive patents in the patent portfolio. All the non-productive patents in the patent portfolio are comprised of patents in the third non-productive patent lists of all the classes in the patent portfolio.

FIG. 4H is displayed when command box 442 is clicked according to an embodiment of the invention. FIG. 4H depicts display of all the non-productive patents in the patent portfolio 444 on display module 110.
FIG. 5 is a flow chart representing a method of eliminating productive patents and identifying non-productive patents according to an embodiment of the invention.
According to an embodiment of the invention, the method of Identifying non¬productive patents is described. At step 500, the patent information for each patent of a patent portfolio is stored in database 106 by control module 100. Thereafter, at step 502, the first class of the patent portfolio is selected, as referred in FIG. 3.
At step 504, control module 100 verifies from user 102 via display module 110 Ihat the first condition, as referred in FIG. 3, is to be received from user 102. in case, the first condition is not to be received from user 102, the first condition is retrieved from database 106 at step 506. In case, the first condition is to be received from user 102, control module 100 receives the first condition inputted by user 102 via input module 104.
At step 510, the first non-productive patent list is determined from the first class by processing module 108 based on the patent information stored in database 106 and the first condition, as referred in FIG. 3.
At step 512, a strength index is calculated by processing module 108 for each patent in the first non-productive patent list using the patent information stored in database 106, as cited in FIG. 3. At step 514, one or more patents are eliminated by processing module 108 from the first non-productive patent list based on the strength index, as referred in FIG. 3. The one or more patents eliminated at step 514 are more productive than the patents which are not eliminated. Further, after eliminating the one or more patents at step 514 the second non-productive patent list is created, as cited in FIG. 3. The second non-productive patent list may comprise lesser number of productive patents than the first non-productive patent list.
At step 516, the cost index is calculated by processing module 108 for each patent in the second non-productive patent list using the patent information stored in database 106, as mentioned in FIG. 3. At step 518, one or more patents are eliminated by processing module 108 from the second non-productive patent list

based on the cost index, as referred in FIG. 3. The one or more patents eliminated at step 518 are more productive than the patents which are not eliminated. Further, after eliminating the one or more patents at step 518 the third non-productive patent list is created, as cited in FIG. 3. The third non-productive patent list may comprise lesser number of productive patents than the second non-productive patent list. The third non-productive patent list is displayed on display module 110 by control module 100 at step 520, as referred in FIG. 4. The third non-productive patent list represents a list of the non-productive patents in the first class of the patent portfolio and has been generated by identification and elimination of productive patents from the patents in the first class of the patent portfolio.
At step 522, control module 100 verifies from user 102 via display module 110 that the patents are to be eliminated from the third non-productive patent list based on a technology activity filter. In case, the patents are to be eliminated based on the technology activity filter; one or more patents are eliminated by processing module 108 from the third non-productive patent list at step 524. In case, the patents are not to be eliminated based on the technology activity filter, step 540 is executed.
According to an embodiment of the invention, the technology activity filter is determined based on the most recently published fonA/ard citation of the patent. The one or more patents are eliminated at step 524 based on the most recently published forward citation of the patent stored in database 106 to create a fourth non-productive patent list. The one or more patents eliminated are more productive than the patents that are not eliminated. The field of the invention of a patent with a later publication date of the most recent forward citation is more active than a patent with an earlier publication date of the most recent forward citation. Therefore, the patent with the later publication date of the most recent forward citation is more productive than the patent with the earlier publication date of the most recent fonA/ard citation. For example, consider that the most recent fonA/ard citation of patent P in the field of networking applications was published on 23'"'' January 1995 and the most recent forward citation of patent Q in the field of wireless technology was as published on 11'1 August 2007, then the field of networking applications is more active than the field of wireless

technology. Therefore, patent P is considered to be more productive than patent Q and hence may be eliminated from third non-productive patent list.
According to another embodiment of the invention, the technology activity filter is determined based on the number of forward citations of the patent in a particular time period. In some embodiments of the invention, the particular time period may be retrieved by control module 100 from database 106. In some embodiments of the invention, the time period may be received from user 102 via input module 104.
Patents with higher number of forward citations in the particular time period are more productive than patents with lower number of forward citations in the particular, time period. The one or more patents are eliminated at step 524 based on the number of foHA/ard citations in the particular time period stored in database 106 to create the fourth non-productive patent list. The one or more patents eliminated at step 524 are more productive than the patents which are not eliminated. Therefore, the fourth non¬productive patent list comprises lesser number of productive patents than the third non-productive patent list. For example, two patents, A and B may have 5 and 10 IbnA/ard citations, respectively from year 2002 to year 2008. Patent B having more forward citations is considered to be a bigger technological milestone than Patent A and further, more products may be produced based on Patent B than patent A. Patent B is thus considered to be more productive than patent A and hence may be eliminated from the third non-productive patent list. The fourth non-productive patent list is displayed on display module 110 by control module 100 at step 526. The fourth non-productive patent list represents a list of non-productive patents in the first class of the patent portfolio and has been generated by identification and elimination of productive patents from the patents in the first class of the patent portfolio.
At step 528, control module 100 verifies from user 102 via display module 110 that the patents are to be eliminated from the fourth non-productive patent list based on the elimination parameters, as referred in FIG. 3. In case, the patents are to be eliminated based on the elimination parameters; control module 100 verifies the source of the elimination parameters at step 530.
Control module 100 verifies user 102 as the source of elimination parameters from database 106, at step 530. According to an embodiment of the invention, the

elimination parameters are received from user 102 via input module 104. According to another embodiment of the invention, the elimination parameters are retrieved from database 106. In case, user 102 is not the source of the elimination parameters, the elimination parameters are retrieved from database 106 at step 532. In case, user 102 is the source of the elimination parameters, control module 100 receives the elimination parameters inputted by user 102 via input module 104 at step 534. User 102 may include or exclude patents in a fifth non-productive patent list based on the elimination parameters. The elimination parameters are described in detail in conjunction with FIG. 3.
At step 536, the fifth non-productive patent list is created by processing module 108 by eliminating one or more patents from the fourth non-productive patent list based on the elimination parameters. Therefore, the fifth non-productive patent list thus comprises lesser number of patents than the fourth non-productive patent list.
The patent geography, as referred in FIG. 3, may be used as an elimination parameter to identify non-productive patents belonging to a geography. According to an embodiment of the invention, only patents belonging to the geography inputted by user 102 are not eliminated from the fourth non-productive patent list and are included in the fifth non-productive patent list. For example, based on the elimination parameter of USA as patent geography, only the patents with the patent geography as USA will be included in the fifth non-productive patent list. According to another embodiment of the invention, only patents belonging to the geography inputted by user 102 are eliminated from the fourth non-productive patent list and are not included in the fifth non-productive patent list. For example, based on the elimination parameter of India as patent geography, only the patents with the patent geography as India will be eliminated from the fourth non-productive patent list and therefore will be excluded from the fifth non-productive patent list.
The fifth non-productive patent list is displayed on display module 110 by control module 100 at step 538. The fifth non-productive patent list represents a list of the non-productive patents in the first class of the patent portfolio. The fifth non¬productive patent list has been generated by the elimination of the patents from the

third non-productive patent list, created at step 518, based on tine technology activity filter and the elimination parameters.
At step 522, in case the patents are verified to be eliminated based on the technology activity filter, then the fourth non-productive patent list is created after the elimination of patents from the third non-productive patent list at step 524. Further, the patents are verified to be eliminated from the fourth non-productive patent list based on the elimination parameters at step 528 to create the fifth non-productive patent list. In case the patents are verified not to be eliminated based on the technology activity filter, then the patents in the third non-productive patent list are verified to be eliminated based on the elimination parameters to create the fifth non-productive patent list at step 540.
At step 540, control module 100 verifies that the patents are to be eliminated from the third non-productive patent list based on the elimination parameters. In case, the patents are to be eliminated based on the elimination parameters; control module 100 verifies the source of the elimination parameters at step 542.
Control module 100 verifies user 102 as the source of elimination parameters, at step 542. According to an embodiment of the invention, the elimination parameters are received from user 102 via input module 104. According to another embodiment of the invention, the elimination parameters are retrieved from database 106. In case, user 102 is not the source of the elimination parameters, the elimination parameters are retrieved from database 106 at step 544. In case, user 102 is the source of the elimination parameters, control module 100 receives the elimination parameters from user 102 via input module 104 at step 546. User 102 may include or exclude patents in the fifth non-productive patent list based on the elimination parameters. The elimination parameters are described in detail in conjunction with FIG. 3.
At step 548, the fifth non-productive patent list is created by processing module 108 by eliminating one or more patents from the third non-productive patent list based on the elimination parameters. The patent geography, as referred in FIG. 3, may be used by user 102 as an elimination parameter to identify non-productive patents belonging to a geography. Patents not belonging to the geography inputted by user 102 are not eliminated from the third non-productive patent list. Therefore, only the

patents belonging to the geography inputted by user 102 are not eliminated from the third non-productive patent list and are included in the fifth non-productive patent list. For example, based on the elimination parameter of USA as patent geography, only the patents with the patent geography as USA will be included in the fifth non¬productive patent list.
The fifth non-productive patent list is displayed on display module 110 by control module 100 at step 550. The fifth non-productive patent list represents a list of the non-productive patents in the first class of the patent portfolio.
FIG. 6 is a flow chart representing a method of receiving and storing patent information of a new patent according to an embodiment of the invention.
According to an embodiment of the invention, a method of receiving and storing the patent information for the new patent which is not present in the patent portfolio, as referred to in FIG. 3, is described. User 102 may add patents in the patent portfolio by adding the patent information of the new patent in database 106. At step 600, the patent information for the new patent is received by control module 100 from user 102 via input module 104. For example, control module 100 may receive the patent information of patent C. The patent information of patent C may comprise the patent number, the phase, the age, the class, the subclass and the number of forward citations of patent C. At step 602, the patent information for the new patent is stored in database 106 by control module 100. The patent information of the new patent after being stored in database 106 becomes part of the patent portfolio.
It is understood that while certain forms of this invention have been illustrated and discussed, it is not limited thereto. However, various alterations may be made thereto without departing from the broader spirit and scope of the invention. The specification and drawings are, accordingly, to be regarded in an illustrative sense rather than a restrictive sense.

1. A computer implemented method of identifying non-productive patents of a
patent portfolio, the method comprising:
i) storing a patent information for each patent of the patent portfolio in a
database; ii) selecting a first class of the patent portfolio; iii) determining a first non-productive patent list from the first class based on
the patent information stored in the database and a first condition; iv) calculating a strength index for each patent in the first non-productive
patent list using the patent information; v) eliminating one or more patents from the first non-productive patent list
based on the strength index, thereby creating a second non-productive
patent list; vi) calculating a cost index for each patent in the second non-productive
patent list using the patent information; vii) eliminating one or more patents from the second non-productive patent
list based on the cost index, thereby creating a third non-productive
patent list; and viii) displaying the third non-productive patent list, wherein the third non¬productive patent list represents a list of non-productive patents in the
first class of the patent portfolio.
2. The method of claim 1 further comprising the steps of:
i) repeating steps (ii)-(viii) for all classes of the patent portfolio;
ii) storing the list of non-productive patents in each class of the patent
portfolio in the database; and iii) displaying a list of all the non-productive patents in the patent portfolio.
3. The method of claim 1 further comprising the step of eliminating one or more patents from the third non-productive patent list based on a technology activity filter.
4. The method of claim 1, wherein the patent information comprises one or more of the following: patent number of a patent, phase of the patent, age of the patent, classification of the patent, number of fonA^ard citations of the patent, date of

publication of forward citations of the patent, sum of all forward citations of patents belonging to sub-class of the patent, number of patents in sub-class of the patent, number of patents in class of the patent, market growth of the class of the patent and discount rate of value of the class the patent.
5. The method of claim 1, wherein the cost index is calculated by using the
formula:
I. — J
wherein,
P is a patent;
1<1 is the subclass of 'p';
c is the class of 'p';
1p is the cost index of 'p';
Psc is the number of patents in 'sc';
Pc is the number of patents in 'c';
f*1p is the number of forward citations of 'p';
f<1sc is the number of fonward citations of all the patents in 'sc';
/ is the current phase of 'p';
« is the maximum number of phases of 'p'; / is an integer between 'j' and 'n';
"'1f is the market growth of 'c' during i'1 phase;
"1fi is the maintenance fee of 'p' during i*1 phase; and
1 is the discount rate of value of 'c' during i'*1 phase.
6. The method of claim 1, wherein the cost index is calculated by using the
formula:

wherein,
P is a patent;

1 is the subclass of 'p';
1 is tlie class of 'p';
'1h is the cost index of 'p';
Psc is the number of patents in 'sc';
Pc is the number of patents in 'c';
f1p is the number of forward citations of 'p';
fcsc is the number of forward citations of all the patents in 'sc';
/ is the current phase of 'p';
1 is the maximum number of phases of 'p'; / is an integer between 'j' and 'n';
"»5f is the market growth of 'c' during i'1 phase; and
1"/i is the maintenance fee of 'p' during i"1 phase. 7. The method of claim 1, wherein the first condition is a time factor. 3. The method of claim 1, wherein the first condition is a list of patent numbers.
9. The method of claim 1 wherein the first condition comprises one or more elimination parameters.
10. The method of claim 1, wherein the first condition is received from a user.
11. The method of claim 1, wherein the first condition is retrieved from the database.
12. The method of claim 1 further comprising the step of eliminating one or more patents from the third non-productive patent list based on one or more elimination parameters.
13. The method of claim 12, wherein the one or more elimination parameters are received from a user.
14. The method of claim 12, wherein the one or more elimination parameters are retrieved from the database.
15. The method of claim 12, wherein the one or more elimination parameters comprises one or more of the following: number of patents required in the third non¬productive patent list, maintenance fee of each patent, patent geography and budgetary constraints.

16. The method of claim 15, wherein the budgetary constraints comprise one or
more of the following: total maintenance fee payable and total maintenance fee
savable.
17. The method of claim 1 further comprising the steps of:
i) receiving a patent information for a new patent; and
ii) storing the received patent information for the new patent in the database.