Enhanced project management tool

• US 8,224,472 B1
• Filed: 09/16/2008
• Issued: 07/17/2012
• Est. Priority Date: 08/25/2004
• Status: Active Grant

• Current Assignee: USA As Represented By The Administrator Of The NASA
• Original Assignee: The United States of America As Represented By The Secretary of Agriculture
• Inventors: Maluf, David A., Hsu, Chen-Jung, Patel, Hemil N., Moh Hashim, Jairon C., Tran, Khai Peter B.
• Primary Examiner(s): Hartman, Jr., Ronald
• Application Number:
  US12/211,439
• Time in Patent Office: 1,400 Days
• Field of Search: 700/97, 700/99, 705/7.11, 705/7.12, 705/7.13, 705/7.14, 705/7.15, 705/7.16, 705/7.17, 705/7.22, 705/7.23, 705/7.28, 705/7, 705/11
• US Class Current: 700/97
• CPC Class Codes: G06Q 10/06 Resources, workflows, human or project management; Enterprise or organisation planning; Enterprise or organisation modelling
• CPC Class Codes: G06Q 10/063 Operations research, analysis or management
• CPC Class Codes: G06Q 10/0631 Resource planning, allocation, distributing or scheduling for enterprises or organisations
• CPC Class Codes: G06Q 10/06311 Scheduling, planning or task assignment for a person or group
• CPC Class Codes: G06Q 10/063112 Skill-based matching of a person or a group to a task
• CPC Class Codes: G06Q 10/063114 Status monitoring or status determination for a person or group
• CPC Class Codes: G06Q 10/063116 Schedule adjustment for a person or group
• CPC Class Codes: G06Q 10/063118 Staff planning in a project environment
• CPC Class Codes: G06Q 10/06312 Adjustment or analysis of established resource schedule, e.g. resource or task levelling, or dynamic rescheduling
• CPC Class Codes: G06Q 10/06313 Resource planning in a project environment

Abstract

A system for managing a project that includes multiple tasks and a plurality of workers. Input information includes characterizations based upon a human model, a team model and a product model. Periodic reports, such as one or more of a monthly report, a task plan report, a schedule report, a budget report and a risk management report, are generated and made available for display or further analysis or collection into a customized report template. An extensible database allows searching for information based upon context and upon content. Seven different types of project risks are addressed, including non-availability of required skill mix of workers. The system can be configured to exchange data and results with corresponding portions of similar project analyses, and to provide user-specific access to specified information.

Claims

1. A system for managing a project that includes a plurality of tasks and a plurality of workers, the system comprising providing a computer that is programmed:

to provide a searchable database and associated system that provides and visually displays information comprising;

a monthly report that reports, at each of at least two times including the present time, present status of each of a plurality of specified tasks and compares the present status of each specified task with an initial estimate of status of the corresponding specified task at the present time;

a task plan report that provides more detail on, and allows quantitative analysis on, at least one of the specified tasks;

a schedule report that provides at least one of a graphical presentation and an alphanumerical presentation of information comparing an schedule of completion of the at least one specified task with a present stage of completion of the at least one specified task;

a budget report that provides at least one of a graphical presentation and an alphanumerical presentation of information on at least one of;

full cost summary to date of at least one of the specified tasks;

worker full time equivalent to date for each worker associated with the at least one specified task;

labor costs expended to date for each worker associated with the at least one specified task;

travel costs expended to date for each worker associated with the at least one specified task; and

overhead allocated to date for each worker associated with the at least one specified task;

a risk management report indicating at least one risk that has been accepted to date to complete the at least one specified task, indicating at least one risk mitigation measure that is proposed or implemented to mitigate the at least one risk, and providing an estimate of present risk that the at least one specified task will not be completed as initially estimated, where the at least one risk is drawn from a set of risks comprising a technical risk concerning performance of at least one product developed as part of the project, a schedule risk that a component of the project will not be completed and delivered according to an anticipated schedule, a budget risk that a component of the project will not be completed and delivered within an accepted budget, a management risk that one or more accepted milestones will not be met;

an in-house worker skills mix risk that in-house personnel with one or more critical skills will not be available to work on the project;

a contractor skills mix risk that contractor personnel with one or more critical skills will not be available to work on the project;

an objectives risk that one or more milestones or goals will not be met within an acceptable time frame;

a skills availability risk report that evaluates a risk of unavailability of at least one critical development skill, needed to meet least one milestone of a project, because of at least one of retirement, departure, reassignment, illness, and other interfering activity for at least one of an in-house worker and a contractor worker; and

a skills evaluation report that considers at least one of the following attributes;

at least one skill or related group of skills asserted to be possessed by the at least one in-house worker;

at least one skill or related group of skills asserted to be possessed by the at least one contractor worker;

depth of the at least one in-house worker'"'"'s skill, as measured by number of years working experience applying the skill or related group of skills;

depth of the at least one contractor worker'"'"'s skill, as measured by number of years working experience applying the skill or related group of skills;

contributions to the at least one in-house worker'"'"'s skill through training, education, apprenticeship and self-learning;

contributions to the at least one contractor worker'"'"'s skill through training, education, apprenticeship and self-learning;

skills reinforcement and skills update training, and dates of the reinforcement and update training, received by the at least one in-house worker;

skills reinforcement and skills update training, and dates of the reinforcement and update training, received by the at least one contractor worker;

at least one example of projects in which the at least one in-house worker has applied this skill in preceding projects; and

at least one example of projects in which the at least one contractor worker has applied this skill in preceding projects.

2. The system of claim 1, wherein said computer is programmed to evaluate at least one of the following risks as a technical risk:

failure of product to meet intermediate or final test during development;

failure to deliver an acceptable product;

delivery of an acceptable, but manifestly unreliable, product;

delivery of an acceptable product after agreed delivery date;

determination that contemplated product cannot work as required; and

possible introduction by a competitor of a competing/superior product.

3. The system of claim 1, wherein said computer is programmed to evaluate at least one of the following risks as a schedule risk:

failure to meet at least one ab initio milestone;

insertion of additional time period to allow investigation of, or response to, unexpected intermediate result; and

unexpected change in milestone schedule.

4. The system of claim 1, wherein said computer is programmed to evaluate at least one of the following risks as a budget risk:

failure to reach at least one ab initio budget milestone within, or near to, an allocated budget increment;

forced “

borrowing”

from a subsequent budget increment to respond to an unexpected problem; and

unexpected change in at least one budget increment allocated to one or more stages of project completion.

5. The system of claim 1, wherein said computer is programmed to evaluate at least one of the following risks as a management risk:

partial or complete unavailability of the required personnel to manage one or more stages of product development within an acceptable time frame.

6. The system of claim 1, wherein said computer is further programmed to permit a system user to select a custom template of one or more of said monthly report, said task plan report, said schedule report, said budget report and said risk management report, presenting information of particular interest to the user.

7. The system of claim 6, wherein said computer is further programmed to permit said user to specify at least one of said monthly report, said task plan report, said schedule report, said budget report and said risk management report that is to be added to, or deleted from, said custom template to be presented to said user.

8. A system for managing a project that includes a plurality of tasks and a plurality of workers, the system comprising providing a computer that is programmed:

to provide a searchable database and associated system that provides and visually displays information comprising;

a monthly report that reports, at each of at least two times including the present time, present status of each of a plurality of specified tasks and compares the present status of each specified task with an initial estimate of status of the corresponding specified task at the present time;

a task plan report that provides more detail on, and allows quantitative analysis on, at least one of the specified tasks;

a schedule report that provides at least one of a graphical presentation and an alphanumerical presentation of information comparing an schedule of completion of the at least one specified task with a present stage of completion of the at least one specified task;

a budget report that provides at least one of a graphical presentation and an alphanumerical presentation of information on at least one of;

full cost summary to date of at least one of the specified tasks;

worker full time equivalent to date for each worker associated with the at least one specified task;

labor costs expended to date for each worker associated with the at least one specified task;

travel costs expended to date for each worker associated with the at least one specified task; and

overhead allocated to date for each worker associated with the at least one specified task;

a risk management report indicating at least one risk that has been accepted to date to complete the at least one specified task, indicating at least one risk mitigation measure that is proposed or implemented to mitigate the at least one risk, and providing an estimate of present risk that the at least one specified task will not be completed as initially estimated, where the at least one risk is drawn from a set of risks comprising a technical risk concerning performance of at least one product developed as part of the project, a schedule risk that a component of the project will not be completed and delivered according to an anticipated schedule, a budget risk that a component of the project will not be completed and delivered within an accepted budget, a management risk that one or more accepted milestones will not be met;

an in-house worker skills mix risk that in-house personnel with one or more critical skills will not be available to work on the project;

a contractor skills mix risk that contractor personnel with one or more critical skills will not be available to work on the project;

an objectives risk that one or more milestones or goals will not be met within an acceptable time frame;

a comparative analysis report comparing the present period with at least one of N1 preceding periods (N1≧

1), with reference to at least one of the technical risk, the schedule risk, the budget risk, the management risk, the in-house worker skills mix risk and the contractor worker skills mix risk,

wherein the computer is further programmed;

to store a version of at least one of the monthly report, the task plan report, the schedule report, the budget report and the risk management report for the present reporting period and for each of the N1 preceding periods;

to provide a subject list of subjects that are covered in the present reporting period version of the stored report;

to receive, from a user, a specification of at least one period, drawn from the present period and the N1 preceding periods, and a specification of at least one subject from the subject list, and to provide, for user read-only access, at least one relevant portion of the report from the at least one specified period; and

to permit the user to indicate and to electronically copy at least one user-selected portion of at least one report, from the stored versions of the at least one report, for at least one of the present period and the N1 preceding periods.

9. The system of claim 8, wherein said computer is further programmed, as part of said monthly report for at least one month:

to provide estimates of a planned value (PV) parameter that reflects cumulative planned project costs to execute stages of a selected project through a present time t, an actual cost (AC) parameter that reflects cumulative actual project costs for the stages of the selected project through the present time and a cumulative earned value (EV) parameter that reflects percentage completion of the selected project through the present time, associated with the selected project for at least first and second selected times during implementation of the selected project;

to perform an earned value management analysis for the selected project for a selected time interval between the first and second selected times; and

to provide at least one graphical display of an estimate of at least one of the PV parameter, the AC parameter and the EV parameter as a function of time in the selected time interval.

10. The system of claim 8, wherein said computer is further programmed:

to provide a lexicon that provides a correspondence of at least one of categories, groups of subjects within categories, and individual subjects, within said reports, and at least one of categories, groups of subjects within categories, and individual subjects for a selected reporting system that provides information similar to information provided by said system; and

to provide a link between at least one of a category, a group of subjects within a category and an individual subject, within said system, and at least one of a corresponding category, a corresponding group of subjects within a category and a corresponding individual subject, within the selected reporting system so that specification of at least one of a category, a group of subjects within a category and an individual subject, within said system, identifies and displays at least one of a corresponding category, a corresponding group of subjects within a category and a corresponding individual subject, within the selected reporting system.

11. The system of claim 8, wherein said computer is further programmed to provide a tool bar for said user that links at least two specified components or at least two specified data sets that are related to each other.

12. A system for managing a project that includes a plurality of tasks and a plurality of workers, the system comprising providing a computer that is programmed:

to provide a searchable database and associated system that provides and visually displays information comprising;

to provide a monthly report that reports, at each of at least two times including the present time, present status of each of a plurality of specified tasks and compares the present status of each specified task with an initial estimate of status of the corresponding specified task at the present time;

to provide a task plan report that provides more detail on, and allows quantitative analysis on, at least one of the specified tasks;

to provide a schedule report that provides at least one of a graphical presentation and an alphanumerical presentation of information comparing an schedule of completion of the at least one specified task with a present stage of completion of the at least one specified task;

to provide a budget report that provides at least one of a graphical presentation and an alphanumerical presentation of information on at least one of;

full cost summary to date of at least one of the specified tasks;

worker full time equivalent to date for each worker associated with the at least one specified task;

labor costs expended to date for each worker associated with the at least one specified task;

travel costs expended to date for each worker associated with the at least one specified task; and

overhead allocated to date for each worker associated with the at least one specified task; and

a risk management report indicating at least one risk that has been accepted to date to complete the at least one specified task, indicating at least one risk mitigation measure that is proposed or implemented to mitigate the at least one risk, and providing an estimate of present risk that the at least one specified task will not be completed as initially estimated, where the at least one risk is drawn from a set of risks comprising a technical risk concerning performance of at least one product developed as part of the project, a schedule risk that a component of the project will not be completed and delivered according to an anticipated schedule, a budget risk that a component of the project will not be completed and delivered within an accepted budget, a management risk that one or more accepted milestones will not be met;

an in-house worker skills mix risk that in-house personnel with one or more critical skills will not be available to work on the project;

a contractor skills mix risk that contractor personnel with one or more critical skills will not be available to work on the project;

an objectives risk that one or more milestones or goals will not be met within an acceptable time frame,

wherein the computer is further programmed;

to provide or receive at least one parameter corresponding to each of at least K alternative investments of resources in K respective projects, numbered k=1, . . . , K (K≧

2), the at least one parameter being drawn from a group of project-defining parameters comprising, for each of the alternative projects;

at least one special technical requirement for completion of the alternative project;

estimated cost of the alternative project;

estimated foregone-opportunity cost of the alternative project;

estimated schedule for completion of the alternative project;

estimated economic return associated with completion of the alternative project;

estimated non-economic return associated with completion of the alternative project; and

estimated skill mix required for personnel working on the alternative project; and

to perform at least one simulation of a scenario associated with completion of the alternative project.

13. The system of claim 12, wherein said computer is further programmed to perform said at least one simulation of said scenario associated with completion of each of said alternative projects, by a process comprising:

providing a projected interest rate i(proj) for each of a selected number N of consecutive periods in the future, numbered n=1, . . . , N (N≧

1);

providing an estimated cost C_n(k) and an estimated return R_n(k) for said alternative project number k, for k=1, . . . , K, for the future period number n;

computing a time value of return TVR(i(proj);

k) for the N periods, using the estimated costs C_n(k), the estimated returns R_n(k), and the projected interest rate i(proj)=i(k) for said alternative project number k according to a relation

14. The system of claim 12, wherein said computer is further programmed to perform said at least one simulation of said scenario associated with completion of said project, by a process comprising:

providing an estimated cost C_n(k) and an estimated return R_n(k) for said project for each of N future periods, numbered n=1, . . . , N (N≧

1) for each of said alternative projects number k;

estimating a largest finite imputed interest value i0(k) for which a computed time value of return, defined as

15. The system of claim 12, wherein said computer is further programmed to perform said at least one simulation of said scenario associated with completion of said project, by a process comprising:

providing an estimated cost C_n(k) and an estimated return R_n(k) for said project for each of N future periods, numbered n=1, . . . , N (N≧

1) for each of said alternative projects number k;

estimating a largest finite imputed interest value i0(k) for which a computed time value of return, defined as

16. The system of claim 12, wherein said computer is further programmed to perform said at least one simulation of said scenario associated with completion of said project, by a process comprising:

providing an estimated cost C_n(k) and an estimated return R_n(k) for said project for each of N future periods, numbered n=1, . . . , N (N≧

1);

for each of said alternative projects, estimating a smallest imputed interest value i0 for which a computed time value of return, defined as

17. A system for managing a project that includes a plurality of tasks and a plurality of workers, the system comprising providing a computer that is programmed:

to provide a searchable database and associated system that provides and visually displays information comprising;

a monthly report that reports, at each of at least two times including the present time, present status of each of a plurality of specified tasks and compares the present status of each specified task with an initial estimate of status of the corresponding specified task at the present time;

a task plan report that provides more detail on, and allows quantitative analysis on, at least one of the specified tasks;

a schedule report that provides at least one of a graphical presentation and an alphanumerical presentation of information comparing an schedule of completion of the at least one specified task with a present stage of completion of the at least one specified task;

a budget report that provides at least one of a graphical presentation and an alphanumerical presentation of information on at least one of;

full cost summary to date of at least one of the specified tasks;

worker full time equivalent to date for each worker associated with the at least one specified task;

labor costs expended to date for each worker associated with the at least one specified task;

travel costs expended to date for each worker associated with the at least one specified task; and

overhead allocated to date for each worker associated with the at least one specified task;

a risk management report indicating at least one risk that has been accepted to date to complete the at least one specified task, indicating at least one risk mitigation measure that is proposed or implemented to mitigate the at least one risk, and providing an estimate of present risk that the at least one specified task will not be completed as initially estimated, where the at least one risk is drawn from a set of risks comprising a technical risk concerning performance of at least one product developed as part of the project, a schedule risk that a component of the project will not be completed and delivered according to an anticipated schedule, a budget risk that a component of the project will not be completed and delivered within an accepted budget, a management risk that one or more accepted milestones will not be met;

an in-house worker skills mix risk that in-house personnel with one or more critical skills will not be available to work on the project;

a contractor skills mix risk that contractor personnel with one or more critical skills will not be available to work on the project;

an objectives risk that one or more milestones or goals will not be met within an acceptable time frame,

wherein said computer is further programmed;

to permit running of at least one test case that executes a selected portion of software that is part of the computer'"'"'s program and provides at least one computed result;

to compare the at least one computed result of execution or presentation of the test case with at least one corresponding known, correct result; and

when the at least one computed result does not substantially agree with the at least one corresponding known, correct result, to note and display this non-agreement in an error log, and to preserve the non-agreement in the error log in a read-only format that cannot be modified, cannot be added to, and cannot be deleted.

18. The system of claim 17, wherein said computer is further programmed:

to permit access by at least one authorized user to said computer in order to modify and to perform further tests on said selected portion of said software;

to permit the at least one authorized user to modify said selected portion of said software to attempt to provide a software fix that removes said non-agreement; and

to provide and display an entry in said error log indicating the software fix provided by the authorized user and indicating where the software fix is located in the modified software.

19. A system for managing a project that includes a plurality of tasks and a plurality of workers, the system comprising providing a computer that is programmed:

to provide a searchable database and associated system that provides and visually displays information comprising;

a monthly report that reports, at each of at least two times including the present time, present status of each of a plurality of specified tasks and compares the present status of each specified task with an initial estimate of status of the corresponding specified task at the present time;

a task plan report that provides more detail on, and allows quantitative analysis on, at least one of the specified tasks;

a schedule report that provides at least one of a graphical presentation and an alphanumerical presentation of information comparing an schedule of completion of the at least one specified task with a present stage of completion of the at least one specified task;

a budget report that provides at least one of a graphical presentation and an alphanumerical presentation of information on at least one of;

full cost summary to date of at least one of the specified tasks;

worker full time equivalent to date for each worker associated with the at least one specified task;

labor costs expended to date for each worker associated with the at least one specified task;

travel costs expended to date for each worker associated with the at least one specified task; and

overhead allocated to date for each worker associated with the at least one specified task;

a risk management report indicating at least one risk that has been accepted to date to complete the at least one specified task, indicating at least one risk mitigation measure that is proposed or implemented to mitigate the at least one risk, and providing an estimate of present risk that the at least one specified task will not be completed as initially estimated, where the at least one risk is drawn from a set of risks comprising a technical risk concerning performance of at least one product developed as part of the project, a schedule risk that a component of the project will not be completed and delivered according to an anticipated schedule, a budget risk that a component of the project will not be completed and delivered within an accepted budget, a management risk that one or more accepted milestones will not be met;

an in-house worker skills mix risk that in-house personnel with one or more critical skills will not be available to work on the project;

a contractor skills mix risk that contractor personnel with one or more critical skills will not be available to work on the project;

an objectives risk that one or more milestones or goals will not be met within an acceptable time frame,

wherein said computer is further programmed;

to require a user of the system to submit a system user identity indicium to authenticate an identity of the user;

to accept, as the system user identity indicium, at least one of a selected group of biometric indicia presented by the user, comprising at least one of at least one of a fingerprint of the user, a voiceprint of the user, a retinal scan of the user, a scan of blood transport channels in a selected region of the user'"'"'s body, a scan of visible features of a selected portion of the user'"'"'s face, and a sample of handwriting of the user; and

when the user'"'"'s identity is authenticated, to receive from the user a specification of information the user seeks, and to indicate one or more use permissions, drawn from a group of permissions comprising permission to read, permission to add to the information, permission to modify the information, and permission to selectively delete at least a portion of the information.

20. A system for managing a project that includes a plurality of tasks and a plurality of workers, the system comprising providing a computer that is programmed:

to provide a searchable database and associated system that provides a visuay display;

to provide a monthly report that reports, at each of at least two times including the present time, present status of each of a plurality of specified tasks and compares the present status of each specified task with an initial estimate of status of the corresponding specified task at the present time;

to provide a task plan report that provides more detail on, and allows quantitative analysis on, at least one of the specified tasks;

to provide a schedule report that provides at least one of a graphical presentation and an alphanumerical presentation of information comparing an schedule of completion of the at least one specified task with a present stage of completion of the at least one specified task;

to provide a budget report that provides at least one of a graphical presentation and an alphanumerical presentation of information on at least one of;

full cost summary to date of at least one of the specified tasks;

worker full time equivalent to date for each worker associated with the at least one specified task;

labor costs expended to date for each worker associated with the at least one specified task;

travel costs expended to date for each worker associated with the at least one specified task; and

overhead allocated to date for each worker associated with the at least one specified task;

to provide or receive at least one parameter corresponding to each of at least K alternative investments of resources in K respective projects, numbered k=1, . . . , K (K≧

2), the at least one parameter being drawn from a group of project-defining parameters comprising, for each of the alternative projects;

at least one technical requirement for completion of the alternative project;

estimated cost of the alternative project;

estimated foregone-opportunity cost of the alternative project;

estimated schedule for completion of the alternative project;

estimated economic return associated with completion of the alternative project;

estimated non-economic return associated with completion of the alternative project; and

estimated skill mix required for workers working on the alternative project; and

to perform at least one simulation of a scenario associated with completion of the alternative project.

21. A system for managing a project that includes a plurality of tasks and a plurality of workers, the system comprising providing a computer that is programmed:

to provide a searchable database and associated system that provides a visual display;

to provide a monthly report that reports, at each of at least two times including the present time, present status of each of a plurality of specified tasks and compares the present status of each specified task with an initial estimate of status of the corresponding specified task at the present time;

to provide a task plan report that provides more detail on, and allows quantitative analysis on, at least one of the specified tasks;

to provide a schedule report that provides at least one of a graphical presentation and an alphanumerical presentation of information comparing an schedule of completion of the at least one specified task with a present stage of completion of the at least one specified task;

to provide a budget report that provides at least one of a graphical presentation and an alphanumerical presentation of information on at least one of;

full cost summary to date of at least one of the specified tasks;

worker full time equivalent to date for each worker associated with the at least one specified task;

labor costs expended to date for each worker associated with the at least one specified task;

travel costs expended to date for each worker associated with the at least one specified task; and

overhead allocated to date for each worker associated with the at least one specified task;

to require a user of said system to submit a system user identity indicium to authenticate an identity of the user;

to accept, as the system user identity indicium, at least one of a selected group of biometric indicia presented by the user, comprising at least one of at least one of a fingerprint of the user, a voiceprint of the user, a retinal scan of the user, a scan of blood transport channels in a selected region of the user'"'"'s body, a scan of visible features of a selected portion of the user'"'"'s face, and a sample of handwriting of the user; and

when the user'"'"'s identity is authenticated, to receive from the user a specification of information the user seeks, and to indicate one or more use permissions for the user, drawn from a group of permissions comprising permission to read, permission to add to the information, permission to modify the information, and permission to selectively delete at least a portion of the information.

22. A system for managing a project that includes a plurality of tasks and a plurality of workers, the system comprising providing a computer that is programmed:

to provide a searchable database and associated system that provides a visual display;

to provide a monthly report that reports, at each of at least two times including the present time, present status of each of a plurality of specified tasks and compares the present status of each specified task with an initial estimate of status of the corresponding specified task at the present time;

to provide a task plan report that provides more detail on, and allows quantitative analysis on, at least one of the specified tasks;

to provide a schedule report that provides at least one of a graphical presentation and an alphanumerical presentation of information comparing an schedule of completion of the at least one specified task with a present stage of completion of the at least one specified task;

to provide a budget report that provides at least one of a graphical presentation and an alphanumerical presentation of information on at least one of;

full cost summary to date of at least one of the specified tasks;

worker full time equivalent to date for each worker associated with the at least one specified task;

labor costs expended to date for each worker associated with the at least one specified task;

travel costs expended to date for each worker associated with the at least one specified task; and

overhead allocated to date for each worker associated with the at least one specified task;

to permit running of at least one test case that executes a selected portion of software that is part of the computer'"'"'s program and that provides at least one computed result;

to compare the at least one computed result of execution or presentation of the test case with at least one corresponding known, correct result; and

when the at least one computed result does not agree with the at least one corresponding known, correct result, to note and display this non-agreement in an error log, and to preserve the non-agreement in the error log in a read-only format that cannot be modified, cannot be added to, and cannot be deleted.