Abstract:
An instantaneous, event driven diagramming method is provided which identifies discrete events within various activities performed during the course of a project and interrelates such events, where applicable, according to the timing and/or functional relationship between such events. An event driven diagram generated in accordance with the method of this invention may be used with CPM, and may be read by a computer employing standard algorithms to determine the critical path of the project.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefit of U.S. Provisional Application Ser. No. 60/839,607 filed Aug. 23, 2006 under 35 U.S.C. § 119(e) for all commonly disclosed subject matter. U.S. Provisional Application Ser. No. 60/839,607 is expressly incorporated herein by reference in its entirety to form part of the present disclosure. 
     
     FIELD OF THE INVENTION 
       [0002]    This invention relates to a diagramming method for portfolio and project management and planning, and, more particularly, to an event driven diagramming method which identifies discrete events within various activities performed during the course of a project and interrelates such events, where applicable, according to the timing and/or functional relationship between such events. 
       BACKGROUND OF THE INVENTION 
       [0003]    Planning is a critical aspect of projects in the field of construction and a variety of other fields. Projects may have a duration of months or years, and construction contracts for example, often include penalty provisions for delays in the completion of a project which may amount to thousands of dollars per day. Project planners must be able to plan the sequence in which work on the project will be performed, and the rate at which resources should be devoted to any given task to avoid delays. Additionally, the plan must be capable of change in view of unforeseen circumstances such as equipment failure, weather issues, labor strikes and a myriad of other events. 
         [0004]    The most commonly used method of modeling the time and criticality of different activities within a project is known as the critical path method or CPM. The CPM method employs a computer algorithm which follows a diagram of every related path in a project through activities, their durations and the relationships between them to determine the longest sequence of activities. The longest sequence of activities is called the “critical path.” A delay in any one of the activities along the critical path results in a delay of the completion date of the overall project. 
         [0005]    Historically, two primary methods of project diagramming have been employed with the CPM method. These include the Arrow Diagramming Method or ADM, and the Precedence Diagramming Method or PDM. Referring initially to  FIG. 1 , a diagram using the ADM method is schematically shown in connection with a road building project. For ease of illustration and discussion, the project is assumed to consist of four activities, namely, clearing and grubbing, excavation, drainage and building the road. In an ADM network, nodes are used and the combination of two nodes denotes a particular activity. Each activity must be defined by a unique pair of nodes. As shown in  FIG. 1 , there are nodes  1 ,  2 ,  3 ,  4  and  5 . Nodes  1  and  2  are connected by line  10  which is indicative of the activity “clearing and grubbing,” and a duration of ten days is attributed to that activity. Nodes  2  and  3  are connected by line  12  and represent the “drainage” activity which is given a duration of eleven days. Nodes  2  and  4 , joined by line  14 , denote the “excavation” activity, and that is assigned a duration of twelve days. Finally, nodes  4  and  5  are connected by line  16  and represent the “building the road” activity having a duration of nine days. 
         [0006]    It is noted from  FIG. 1  that the duration of the drainage activity is less than the excavation activity by one day. In order for the computer to follow the diagram from beginning to end along the path encompassing the drainage activity, a line  18  is inserted between nodes  3  and  4  denoting a “dummy” activity. There is no activity represented by line  18  and the node path  3  to  4 , and therefore a zero duration is attributed to that node pair. Consequently, a day of “float” or permitted delay is present between the end of the drainage activity and the end of excavation, i.e. it takes five days to complete excavation and only four days for drainage, and therefore drainage can be delayed by one day without affecting the completion date of the project. The total float of any sequence of activities is equal to the amount of time a sequence of activities can be delayed before delaying the completion date of the entire project. 
         [0007]    Employing the CPM method with the arrow diagram shown in  FIG. 1  it is noted that the “critical path” or longest sequence of activities occurs along the pathway of nodes  1  to  2 ,  2  to  4  and  4  to  5  for a total of thirty-one days. The other path evident in  FIG. 1  is that along nodes  1  to  2 ,  2  to  3 ,  3  to  4  and  4  to  5  for a total of thirty days, or one day less than the critical path. 
         [0008]    The example depicted in  FIG. 1  illustrates the basic premise of arrow diagramming, i.e. a network is established by diagramming activities using pairs of nodes, and relating one activity to another by their starts and finishes. One problem with the ADM method is apparent when it is desired to obtain a more precise model of a project where activities are not related by their starts or finishes. For example, in the example shown in  FIG. 1  it is assumed that the drainage and excavation activities do not begin until the end of clearing and grubbing, and that building the roadway does not commence until the drainage and excavation activities have been completed. As a practical matter, a contractor would likely want to begin the drainage and excavation activities at some point after the start of the clearing and grubbing activity but before such activity has been completed. Similarly, building of the road would typically follow the clearing and grubbing, drainage and excavation activities at some point before they are finished. Because the ADM method depends on the use of pairs of nodes to denote a particular activity, when the plan becomes more complicated and one or more activities do not necessarily begin at the start or finish of another activity, a number of dummy nodes or extra activities must be incorporated into the diagram network. This results in a loss of the original activity structure and a great deal of confusion. 
         [0009]    The Precedence Diagramming Method or PDM was developed to improve upon ADM diagramming, and is currently the plan diagram most commonly used with the CPM method. Precedence diagramming is predicated upon identifying unique activities and then establishing relationships between the starts or finishes of such activities. Referring now to  FIG. 2 , the same roadway construction project described in connection with a discussion of  FIG. 1  is illustrated with the PDM method. Instead of focusing on the relationships between activities as in the ADM method, the PDM method identifies activities, each having a start and a finish, with an assigned duration for each activity. The clearing and grubbing activity is identified by the box labeled with the reference number  20 , with start and finish positions indicated within the box  20  as well as a duration of ten days. The PDM method provides for improved flexibility, compared to the ADM model, and this is demonstrated in  FIG. 2  by the introduction of “lag” into the relationships between activities. As noted above, the building contractor may wish to begin the excavation and drainage activities of the road building project before the completion of the clearing and grubbing operation. The “start” of the clearing operation  10  is thus shown in  FIG. 2  as being connected by a line  22  to the start of the excavation activity, depicted as box  24 , with a positive lag  26  of plus two days interposed between the start of such activities. This indicates to the planner that the excavation activity  24  may “lag” or begin two days after the start of the clearing operation  20 . 
         [0010]    The other activities of the project are related to one another, e.g. start-to-start, start-to-finish, finish-to-finish or finish-to-start, in a similar manner. The drainage activity, indicated by box  28 , is connected by a line  30  to the start of the clearing and grubbing activity  20  with a positive lag  32  of plus four days between the start of same. The duration of the excavation activity  24  and drainage activity  28  are shown in their respective boxes. The finish of the excavation activity  24  and finish of the drainage activity  28  are associated with the start of the road building activity, identified by reference number  34  in  FIG. 2 . The finish of the excavation activity  24  is connected to the start of the road building activity  34  by a line  36  with a negative lag  38  of minus three days between the two, and the finish of the drainage activity  28  is connected by a line  40  to the start of the road building activity  34  with a negative lag  42  of three days between them. The “negative” lag in this context means that the road building activity  34  may start three days prior to the finish of the excavation and drainage activities,  24  and  28 , respectively, as distinguished from a “positive” lag wherein the start of an activity must follow another activity such as described above. The finish of the excavation activity  24  and the drainage activity  28  are connected to the finish of the road building activity  34  via lines  46  and  48 , respectively. The finish of the clearing and grubbing activity  20  is connected to the finish of excavation  24  by line  50  and to the finish of drainage  28  by line  52 . 
         [0011]    While the PDM method adds some degree of clarity compared to the ADM method, the planner is still left to guess about a number of things. There is no indication in the PDM network of what the lags  26 ,  32 ,  38  and  42  represent. Further, there is no indication of what events take place within a given activity, how the duration of an activity is determined and/or what is the duration between events within an activity. 
         [0012]    Another significant limitation of both the ADM and PDM methods involves determining the status of a particular project at a selected point in time. The road construction project discussed as an example above is very simple and of limited duration. Many projects, however, may comprise hundreds of activities and take months or years to complete. It is desirable to determine the status of the critical path on a regular basis to identify problem areas which could impact the completion date of the project, and allow planners to allocate materials and manpower accordingly. Complicated projects of relatively long duration typically employ “data dates,” often once a month, at which time a “snapshot” is taken of the status of currently pending activities of the project. This snapshot involves obtaining a percentage completion date on each of the pending activities from the contractor(s) in charge of the project. In other words, the contractor must provide his best estimate of how far along each currently active activity is toward completion, on a percentage basis, as of the data date. Percentage completion dates are inherently subjective and are difficult to accurately estimate which can lead to appreciable error in the ensuing calculation of the critical path. Moreover, it is not uncommon for the actual calculation of the critical path based on percentage completion dates to take several weeks to perform, at which time the project has moved forward for that amount of time and the critical path calculation is dated and of questionable value. 
       SUMMARY OF THE INVENTION 
       [0013]    This invention is directed to an instantaneous, event driven diagramming method which identifies discrete point-in-time events within various activities performed during the course of a project and interrelates such events, where applicable, according to the timing and/or functional relationship between such events. An event driven diagram generated in accordance with the method of this invention may be used with CPM, and may be read by a computer employing standard algorithms to determine the critical path of the project. 
         [0014]    The event driven diagramming method of this invention is predicated on the observation that it is not necessarily the start or finish of one activity that relates to the start or finish of another activity. Rather, it is the discrete events within activities, and/or when such events occur, that relate to discrete events within another activity. As described in detail below, in the diagramming method of this invention each event is identified by a description of that event appearing within a “box” in a diagram. Events are related to one another in the sense that one event follows another, and the relationship between related events is represented by a line connecting the two in the diagramming method herein. Each event does not have a duration in and of itself, but represents an instantaneous point in time. As such, the boxes which identify each event are not assigned a duration. Instead, the durations are assigned to the relationships between events, and the durations between given events represent the amount of time it takes from the instantaneous point-int-time of one event to the instantaneous point-in-time of a succeeding event. The duration of any particular activity within a project is the aggregate of the durations between the discrete events within that activity. 
         [0015]    Once discrete events are identified within the various activities of a project, it is the pathway through these events, and the duration of the relationships between them, that determines when activities become critical. Unlike prior ADM or PDM diagramming methods, the event driven method of this invention identifies, instantaneously, at what event an activity will become critical or not critical. Some activities may become critical or not critical after they start or before they finish, depending upon such factors as delay or acceleration in the completion dates of their discrete events. 
         [0016]    Updating the event driven network of this invention can follow two paths. Only currently active activities and relationships create an impact to the critical path. When a delay or acceleration occurs, it is recorded for the day it occurs. The duration between the events impacted by the delay or acceleration is modified accordingly when a computer, employing a conventional CPM algorithm, reaches this date. The project is updated each day with the subject diagramming method, with a record of cumulative losses and gains in time, and their causes. Secondly, with respect to revisions to the plan, all revisions are accompanied by an inception date. When the CPM algorithm reaches the inception date, it revises the schedule accordingly and continues on with the calculation of critical path. Losses or gains due to revisions are quantified and separated from those due to progress. 
         [0017]    The progress of any activity using the method of this invention is determined by whether or not the events within that activity have taken place or not. Unlike the highly subjective percent completion method of determining the status of a project employed in the ADM and PDM methods discussed above, the completion date of an event involves an objective determination on the part of the scheduler. An event has either occurred or it has not. The guesswork of whether an activity is 20% completed or 80% completed is eliminated from the method of this invention. This removes the need for having artificially established data dates, noted above, where a snapshot of the progress of various current activities of a project is taken in order to attempt to ascertain whether or not the project is on schedule. Consequently, schedules can be continuous through time with the method of this invention and updated instantaneously on the basis of whether events have taken place, and, if so, at what time. The planner and contractor are not limited to a separate schedule with each data date update, but rather can have one schedule continuously updated while retaining all of the detail of the history of the project pertaining to time lost or gained up to the last update or revision. 
         [0018]    Among the important purposes of obtaining updates of the project during its execution is to permit contractors to know where to best place their resources, and project managers to know what is impeding or accelerating progress. The percent completion and data date approach employed in the prior art is not only subjective but in most instances results in the provision of information which is too dated to be of much use. The event driven diagramming method of this invention, by providing for one continuous schedule, dramatically improves the information available to contractors and program managers, in terms of accuracy, clarity and timing. Data is available on a real time basis, and there is no guesswork involved in determining whether an event within an activity is completed or not. As such, trends in the schedule and forecasts can be assessed with the method herein prior to their impact on the overall project. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0019]    The structure, operation and advantages of the presently preferred embodiment of this invention will become further apparent upon consideration of the following description, taken in conjunction with the accompanying drawings, wherein: 
           [0020]      FIG. 1  is a flow chart diagram of a road building project using the prior art Arrow Diagramming Method; 
           [0021]      FIG. 2  is a flow chart diagram of a road building project using the prior art Precedence Diagramming Method; and 
           [0022]      FIG. 3  is a flow chart diagram of a road building project using the event driven diagramming method of this invention 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0023]    The prior art Arrow Diagramming Method and Precedence Diagramming Method have been described above in connection with a discussion of  FIGS. 1 and 2 , respectively. Referring now to  FIG. 3 , the event driven diagramming method according to this invention is illustrated using the same road building example as in  FIGS. 1 and 2 . It should be understood that the road building example is intended for purposes of illustration only, and the method of this invention can be employed with a variety of different projects, construction or otherwise, having essentially any level of complexity. 
         [0024]    As noted above, the initial task in diagramming a project with the method of this invention is to identify the different activities to be undertaken during the course of a project, and then to list the events within each activity which will take place from the start of such activity to its completion. Each event must be uniquely identified. In the road building example, there are four activities, namely, clearing and grubbing, excavation, drainage and road building. Each of these activities, and the point-in-time events within them, are described separately below. 
         [0025]    The clearing and grubbing activity is identified by the box  60 , depicted in phantom lines in  FIG. 3 . This activity comprises a number of discrete events, each denoted by a separate box. These events include box  62  denoting “commence delivery of equipment for clearing and grubbing,” box  64  for “begin work,” box  66  for “room for excavation and drainage,” box  68  for “finish work,” and box  70  for “complete removal of equipment.” As discussed above, the descriptive notations contained in the boxes  62 - 70 , and the diagramming method of this invention, define each event in terms of an instantaneous point in time. There is an instantaneous point in time at which the event “commence delivery of equipment for clearing and grubbing”  62  takes place. The boxes  62 - 70  are connected by lines for purposes of illustrating the relationship between events, i.e. one event succeeds another event. A duration is assigned to the relationship between events, as represented in  FIG. 3  by a number next to each line, but the events themselves are not given a duration in the diagramming method herein. 
         [0026]    In the particular example of this invention illustrated in  FIG. 3 , a line  72  extends between box  62  and  64  which is labeled with the number “2.” This denotes that according to the project plan it will take two days from the “commence delivery of equipment for clearing and grubbing” event  62  until the “begin work” event  64  occurs. The event represented by box  62  is not given a duration. Instead, the relationship between the event represented by box  62  and the event represented by the related, succeeding event denoted by box  64  has a duration of “2” days in this example. 
         [0027]    Line  74  between box  64  and  66  refers to a time period, marked with the number “2” after which work on clearing and grubbing has progressed to a point where there is “room for excavation and drainage” as depicted in box  66 . An important conceptual aspect of the method of this invention is predicated upon the realization that in project planning the start of one activity is not necessarily related to the start or finish of another activity, and one or more events within a given activity may be related not only functionally to an event in another activity but temporally. Box  66  is a good example of this aspect of the present invention. It is recognized by the contractor that after two days of clearing and grubbing, enough “room” or physical space has been cleared to allow excavation and drainage to begin in the area which has been cleared. There is no functional relationship between clearing and grubbing, and excavation or drainage as such, e.g. in the sense that the same equipment, for example, is used to perform these activities. However, these activities are related to one another temporally, and the event “room for excavation and drainage”  66  is a “trigger” or starting point in time for the beginning of work event in excavation and beginning of work event in drainage, as discussed below. The method of this invention has the capability of visually depicting this relationship in a diagram, and also linking the trigger event (room for excavation and drainage) to events (begin work) in other activities (excavation and drainage). Neither of the prior art diagramming methods described above has this capability, or anything remotely like it. As noted above, the PDM method for example, is based on start-to-start, start-to-finish, finish-to-start or finish-to-finish relationships. In order to represent the “room for excavation and drainage” function and relate it to excavation and drainage in the PDM method, the clearing and grubbing activity would have to be linked to the excavation and drainage activities with a “lag” inserted to account for the start of such activities before the completion of the clearing and grubbing activity. One reading such PDM diagram would have no idea what this lag represents, or the events within either clearing and grubbing, excavation or drainage that such lag relates to. This is a serious deficiency of prior art diagramming methods which is solved by the present invention. 
         [0028]    Continuing within the clearing and grubbing activity  60 , the room for excavation and drainage box  66  is connected by a line  76  to the finish work box  68  with a duration of 5 days given to the relationship between those two events. The relationship between the finish work event  68  and the complete removal of equipment event  70  is represented by line  78  and is given a duration of one day. It should be understood that the events depicted in the clearing and grubbing activity  60  are intended for purposes of illustration and there could be more events depending upon circumstances. For example, after the commencement of work on clearing and grubbing an unforeseen event could arise that creates a delay, e.g. repair or replacement of damaged or defective equipment, an encounter with rock or other unexpected obstacle which delays clearing, etc. These situations may be added to the clearing and grubbing activity  60  as discrete events identified by their own box, with an assigned duration to a succeeding event, on the day they occur. Such an update may or may not affect the critical path but the method of this invention allows that to be determined on a continuous basis, e.g. every day as a result of the addition of such event(s). A particular activity may become critical during its performance, where at the inception of the project such activity may not be considered critical, but the method of this invention allows that determination to be made on a continuous basis. Consequently, the contractor has the opportunity to reallocate resources to take care of the problem on a timely basis before it does become critical, i.e. affects the overall completion date of the project. 
         [0029]    Referring now to the top of  FIG. 3 , the dotted line box  80  represents the excavation activity of the road building project. This activity begins with a “commence delivery of equipment for excavation” event depicted as box  82 , and includes a “begin work” event identified as box  84 , a “finish work” event denoted by box  86  and a “complete removal of equipment” event shown as box  88 . It is noted that many of the events within the excavation activity  80  have the same name as those in the clearing and grubbing activity  60 . This is permissible so long as each event is given a unique identity. That is accomplished by identifying the events as being associated with a particular activity; hence, the structure of the diagram illustrated in  FIG. 3  with separate boxes for each activity. Boxes  82  and  84  are connected by a line  90  assigned a duration of “2” days, a line  92  connects boxes  84  and  86  with a duration of “8” days and line  94  connects boxes  86  and  88  with a duration of “2” days. The lines  90 - 94  are intended to signify the relationships between events  82 - 88  in terms of time and sequence, and the durations of such relationships, in the same manner as described above in connection with a discussion of the clearing and grubbing activity  60 . 
         [0030]    As noted above, there is a temporal relationship between the “room for excavation and drainage” event  66  of the clearing and grubbing activity  60  and the excavation activity  80 . This relationship is depicted by a line  96  which connects event box  66  with the “begin work” event  84  of the excavation activity  80 . These two events are not related to one another functionally, but temporally, i.e. at the time the “room for excavation and drainage” event  66  within the clearing and grubbing activity  60  occurs, then the work may begin in excavation (box  84 ). The event driven diagram of this invention clearly identifies this relationship, making it easy for one reading it to determine the sequence of events and the relationship between them. There is no “trigger” as such for the delivery of equipment event  82  in the excavation activity  80 , but it is clearly identified in the diagram and is noted by the computer reading the diagram. Additionally, the “finish work” box  68  of the clearing and grubbing activity  60  is connected by a line  98  to the “finish work” box  86  of the excavation activity  80 . 
         [0031]    Referring now to the bottom of  FIG. 3 , the dotted line box  100  represents the drainage activity of the road building project. This activity  100  has essentially the same nominal events as the excavation activity  80  described above. The drainage activity  100  begins with a “commence delivery of equipment for drainage” event depicted as box  102 , and includes a “begin work” event identified as box  104 , a “finish work” event denoted by box  106  and a “complete removal of equipment” event shown as box  108 . All of these events  102 - 108  have the same name as those in the excavation activity  80 , but are given a unique identity as being associated with the drainage activity  100 . Boxes  102  and  104  are connected by a line  110  assigned a duration of “2” days, a line  112  connects boxes  104  and  106  with a duration of “7” days and line  114  connects boxes  106  and  108  with a duration of “2” days. The lines  110 - 114  are intended to signify the relationships between events  102 - 108  in terms of time and sequence, and the durations of such relationships, in the same manner as described above in connection with a discussion of the clearing and grubbing activity  60 . Just as with the excavation activity  80 , and for the same purpose as described above, there is a temporal relationship between the “room for excavation and drainage” event  66  of the clearing and grubbing activity  60  and the drainage activity  100 . This relationship is depicted by a line  116  which connects event box  66  with the “begin work” event  104  of the excavation activity  80 . Additionally, the “finish work” box  68  of the clearing and grubbing activity  60  is connected by a line  118  to the “finish work” box  106  of the excavation activity  100 . 
         [0032]    Finally, the road building activity is shown in the dotted line box  120  in the center of  FIG. 3 . The road building activity  120  has essentially the same nominal events as the excavation activity  80  and drainage activity  100  described above. The road building activity  120  begins with a “commence delivery of equipment for road building” event depicted as box  122 , and has a “begin work” event identified as box  124 , a “finish work” event denoted by box  126  and a “project complete” event shown as box  128 . While many of these events have the same names as those in the excavation activity  80  and drainage activity  100 , they are given a unique identity as being associated with the road building activity  120 . Boxes  122  and  124  are connected by a line  130  assigned a duration of “1” day, a line  132  connects boxes  124  and  126  with a duration of “6” days and line  134  connects boxes  126  and  128  with a duration of “2” days. The lines  130 - 134  are intended to signify the relationships between events  122 - 128  in terms of time and sequence, and the durations of such relationships, in the same manner as described above in connection with a discussion of the other activities  60 ,  80  and  100 . 
         [0033]    A “trigger” or temporal relationship exists between the “finish work” events  86 ,  106  of the excavation and drainage activities  80 ,  100 , respectively, and the “begin work” event of the road building activity  124 . The project planning calls for the road building work to begin after the completion of the excavation and drainage work. To signify this temporal relationship in the diagram, the finish work event  86  of the excavation activity  80  is connected by a line  136  to the begin work event  124  of the road building activity  120 , and a line  138  connects the finish work event  106  of the drainage activity  100  with such begin work event  124 . The “complete removal of equipment” events  70 ,  88  and  108  of the clearing and grubbing activity  60 , excavation activity  80  and drainage activity  100 , respectively, are connected by respective lines  140 ,  142  and  144  to the project complete event  128  of the road building activity to denote completion of the entire project. 
         [0034]    Throughout the duration of the project, each discrete event in all of the activities is represented as “open” or “completed.” There is no provision for the highly subjective “percent completed” designations employed in prior art diagramming methods. For example, either the commence delivery of equipment event for clearing and grubbing denoted by box  62  has taken place, or it has not, and an objective determination can be made of that fact one way or the other. Data is entered on a daily basis to indicate whether each currently active event is still open or has been completed, and this enables the project to be essentially continuously updated throughout its duration. 
         [0035]    As discussed above, each of the events in the project must be uniquely identified. The diagramming method of this invention is intended to be used with software capable of interfacing with CPM algorithms. One way of uniquely identifying each event within the project is to provide a library of events and a separate listing of the activities for a particular project within the software. The diagram is constructed by assigning particular events from the library of events to each activity. For example, a “begin work” event is identified in the library of events and assigned as depicted by box  64  to the clearing and grubbing activity  60 . Although the “begin work” event from the library will also be used in the excavation, drainage and road building activities  80 ,  100  and  120 , respectively, each one of these “begin work” events is uniquely identified in those activities, e.g. by boxes  84 ,  104  and  124 , because it is assigned from the library to a different activity. In this manner, a library of events may be constructed with many “generic” or often used events, but when assigned to a particular activity each such event is uniquely identified. This feature of the present invention greatly simplifies and expedites diagramming of a project plan. 
         [0036]    While the invention has been described with reference to a preferred embodiment, it should be understood by those skilled in the art that various changes may be made and equivalents substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. 
         [0037]    For example, it is noted above that each event within all activities must be uniquely identified. In the simplified example of road building discussed above, events in different activities are the same but no event within the same activity is repeated. A complicated construction project may have hundreds of activities and many events within separate activities that are nominally the same, e.g., “pouring of concrete,” for example. It is nevertheless contemplated that each “pouring of concrete” event can be uniquely identified as required in the method herein such as by referencing the location or structure of the concrete pour. 
         [0038]    Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims.