This class is a representation of Precedence Diagramming Method (PDM). PDM is a technique used for constructing a schedule model in which activities are represented by nodes and are graphically linked by one or more logical relationships to show the sequence in which the activities are to be performed.
A schedule has activities and relations data-frames. With this class, it is possible to apply critical path method
titleA project title for identification. It depends on user of the class. Its use are:
Sechedule$title <- "A title"
sets a title for a project.
Sechedule$title
gets the title of the project.
referenceA reference from project origin, for example, a book, a paper, a corporation, or nothing. Its uses are:
Sechedule$reference <- "A reference"
sets a reference for a project.
Sechedule$title
gets the reference of the project.
has_any_activityA logical value that indicates if the schedule has any activity. A TRUE value means that the schedule has some activity; a FALSE, means that the schedule is empty.
Usage: Schedule$has_any_activity
nr_activitiesNumber of activities in a schedule as an integer value.
Usage: Schedule$nr_activities
activitiesReturn a data frame with all activities of a schedule in an activity id order. This is the main information calculated by CPM. The data frame is formed by following structure:
id: Activity id.
name: The name of activity.
duration: A number that represents the activity's duration.
milestone: A milestone is an activity with zero duration.
This property indicates if an activity is a milestone or not:
TRUE indicates it is a milestone; FALSE indicates it is not.
critical: A critical activity is one with total float minor or equal
to zero. This property indicates if an activity is critical:
TRUE indicates it is critical;
FALSE indicates it is not critical.
ES: Early Start: is the earliest start period an activity can begin after its predecessors without violating precedence relation.
EF: Early Finish: is the early start plus activity duration.
LS: Late Start: is the late finish minus activity duration.
LF: Late Finish: is the latest finish an activity can finish before their successors without violating precedence relation.
total_float: It is the amount of period an activity can be delayed without violating the project duration. Its formula is: LS - ES or LF - EF.
free_float: It is the amount of period an activity can be delayed without violating the start time of the successors activities.
progr_level: Progressive level is the rank of activities counted from begin. The level of the activities that don't have predecessor is one; the level of the other activities, is one plus the maximal level of their predecessor.
regr_level: Regressive level is the rank of activities counted from the end. The level of the activities that don't have successor is the maximal progressive level; the level of the other activities, is one minus the minimal level of their successor.
topo_float: It is the difference between progressive level and regressive level.
Usage: Schedule$activities
has_any_relationA logical value that indicates if the schedule has any relation. A TRUE value means that the schedule has some relation; a FALSE, means that the schedule does not have any relation.
Usage: Schedule$has_any_relation
nr_relationsNumber of relations in a schedule as an integer value.
Usage: Schedule$nr_relations
relationsReturn a data frame with all relations of a schedule in topological order. This is the main information calculated by CPM. The data frame is formed by following structure:
from: Predecessor activity id from a relation.
to: Successor activity id from a relation.
type: The type of relation between activities. Its value may be: FS, FF, SS, SF.
lag: The time period between activity predecessor and activity successor activity
critical: A critical relation formed by two activity critical:
predecessor and successor.
TRUE indicates it is critical;
FALSE indicates it is not critical.
ord: Indicates de order that the relation was added in the schedule.
i_from: It is the index of predecessor activity in the activities data frame.
i_to: It is the index of successor activity in the activities data frame.
Usage: Schedule$relations
durationAn integer value that indicates the duration of a schedule.
new()Make a schedule with activities and relations between activities.
The method Schedule$new(activities, relations)
creates an schedule object from two data frames,
one containing activities lists and the other the precedence relations
between activities.
After creation, it is applied the Critical Path Method (CPM).
It is possible to create a empty schedule, without any activity or relation
with the constructor Schedule$new().
After that, it is possible to add activity with add_activity
and relation with add_relation methods.
Schedule$new(activities = NULL, relations = NULL)
activitiesData frame with activities. If it is not informed, the schedule will be created without any activity. Its structure is:
id: Activity id. It is an integer number that must be unique within a schedule.
name: Activity name. It may be empty.
duration: Activity duration. It is integer number without unit time. It may be zero.
relationsData frame with precedence relations between activities. If it is informed, the activities has to be informed too. If it is not informed, the schedule will be created without any relation. It is formed by predecessor activity e successor activity. Its structure is:
from: The id of predecessor activity. Must exist an activity with from id.
to: The id of successor activity. Must exist an activity with to id.
type: Specifies the type of relation between activities. The default type is FS and its value may be: FS, FF, SS, SF, that means:
FS: Finish-Start relation. Activity to_id can only start after the finish of activity from_id.
FF: Finish-Finish relation. Activity to_id must finish together with activity from_id.
SS: Start-Start relation. Activity to_id must start together with activity from_id.
SF: Start-Finish relation. Activity to_id must finish when activity from_id starts.
lag: The time period between activities that the successor activity must be advanced, or lated, after activity from_id. It must be an integer, less than, equal or greater than zero.
A Schedule object with CPM parameters calculated.
add_activity()Add an activity to a schedule.
Schedule$add_activity(id, name = "", duration = 0L)
idActivity id that will be used to make relation between activities. It must be unique.
nameThe name of activity. The default is an empty string.
durationA number that represents the activity's duration. It must be equal or greater than zero. The default value is zero.
A Schedule object with an activity added and the critical path calculated.
add_activities()Add activities from a data frame to a schedule.
Schedule$add_activities(activities)
activitiesA data frame with the activities to be added.
A Schedule object with activities added and CPM calculated.
get_activity()Gets an activity by id. It returns a data frame with one line about activity.
Schedule$get_activity(id)
idAn activity id as defined by the user.
A data frame with one line with the activity, or an error if activity id doesn't exist.
add_relation()Add a relation to a schedule.
Schedule$add_relation(from, to, type = "FS", lag = 0L)
fromThe id of predecessor activity. Must exist an activity with from.
toThe id of successor activity. Must exist an activity with to.
typeSpecifies the type of relation between activities. The default type is FS and its value may be: FS, FF, SS, SF, that means: If type is not defined, it is assumed to be FS.
FS: Finish-Start relation. Activity 'to' id can only start after the finish of activity 'from' id.
FF: Finish-Finish relation. Activity 'to' id must finish together with activity 'from' id.
SS: Start-Start relation. Activity 'to' id must start together with activity 'from' id.
SF: Start-Finish relation. Activity 'to' id must finish when activity 'from' id starts.
lagThe time period between activities that the successor activity 'to' must be advanced after activity 'from' has been finished. The value may be negative, in such case, the activity 'to' will be anticipated 'lag' time periods. It must be an integer, less than, equal or greater than zero. If lag is not defined, it is assumed to be zero.
A Schedule object with CPM parameters calculated.
add_relations()Add relations between activities from a data frame to a schedule.
Schedule$add_relations(relations)
relationsA data frame with the relations to be added.
A Schedule object with relations added and CPM calculated.
add_act_rel()Add an activity and her relations to a schedule.
Schedule$add_act_rel( id, name, duration, relations_id = c(), direction = "succ" )
idActivity id. The id will be used to make relation between activities.
nameThe name of activity.
durationA number that represents the activity's duration. It must be equal or greater than zero.
relations_idA vector of ids such that will be linked with activity id. It may be relations of successor or predecessors.
directionDirection of relations_id: It may be "succ" or "pred". If dir="succ" the relations_id will be the successor of the activity. If dir="pred" the relations_id will be the predecessor of the activity.
A Schedule object.
print()Print a description of the class
Schedule$print(...)
...Variable parameters
A String .
all_successors()List all successors from an activity: direct and indirect successors.
Schedule$all_successors(id, ign_to = NULL)
idActivity id to be listed.
ign_toA relation to be ignored: id -> ign_to. Activities from this relation will be ignored.
A vector whith all activities ids.
all_predecessors()List all predecessors from an activity: direct or indirect predecessors.
Schedule$all_predecessors(id, ign_from = NULL)
idActivity id to be listed.
ign_fromA relation to be ignored: ign_from -> id. Activities from this relation will be ignored.
A vector with all activities ids.
is_redundant()Verify if a relation between two activities is redundant. A relation A->C is redundant if there are A->C, A->B, B->C relations.
Schedule$is_redundant(id_from, id_to)
id_fromFrom activity id.
id_toTo activity id.
A logical TRUE if an arc is redundant;
FALSE if it is not.
change_durations()Change activities duration and calculate critical path. This way is faster than creating a new schedule with new durations.
Schedule$change_durations(new_durations)
new_durationsA vector with new activities' duration.
A Schedule object.
gantt_matrix()Create a matrix that represents a Gantt chart, a matrix where "1" indicates that an activity is planned to be in execution.
In this matrix, the rows represent activities, whereas the columns represents the activity execution period. So, the number of columns is equal to project duration.
Schedule$gantt_matrix()
A matrix where "1" indicates that an activity is in execution.
xy_gantt_matrix()Transform a Gantt matrix in x, y coordinates and the weight one. Each point greater than zero in a Gantt matrix becomes a x, y coordinate.
Schedule$xy_gantt_matrix(gantt = NULL)
ganttA Gantt Matrix. If it is not informed, it will use
gantt_matrix() before this function.
A matrix x, y and weight.
topoi_sp()SP Serial or Parallel Topological Indicator: It shows the closeness of a network to a serial or parallel graph. As the network becomes serial, the SP increase, until one, when the network totally serial.
Schedule$topoi_sp()
A number between 0 and 1, inclusive.
topoi_ad()AD Activity Distribution Topological Indicator: Measures the distribution of the activities over the levels. If AD is approximately equal zero, each level has same numbers of activities. Otherwise, if AD is equal one, the quantity of each level is not uniformly distributed.
Schedule$topoi_ad()
A number between 0 and 1, inclusive.
topoi_la()LA Length of Arcs Topological Indicator: Measures the presence of long arcs based on the difference between the progressive level of the end activity and the start node of each relation. If LA is approximately equal zero, the progressive level between activities is as far as possible. Otherwise, if LA is equal one, the relation distance are one.
Schedule$topoi_la()
A number between 0 and 1, inclusive.
topoi_tf()TF Topological Float Indicator: Measures the topological float of each activity. If TF = 0, there is no float between activities. If TF = 1, there is float between activities and they be shift without affecting other activities.
Schedule$topoi_tf()
A number between 0 and 1, inclusive.
clone()The objects of this class are cloneable with this method.
Schedule$clone(deep = FALSE)
deepWhether to make a deep clone.
Csardi, G. & Nepusz, T. (2005). The Igraph Software Package for Complex Network Research. InterJournal. Complex Systems. 1695.
Project Management Institute (2017) A Guide to the Project Management Body of Knowledge (PMBOK Guide). Sixth Edition.
Project Management Institute (2017) PMI Lexicon of Project Management Terms: Version 3.2.
Vanhoucke, M. (2009) Measuring Time: Improving Project Performance Using Earned Value Management. Springer-Verlag US.
Vanhoucke, M. (2013) Project Management with Dynamic Scheduling: Baseline Scheduling, Risk Analysis and Project Control. Springer-Verlag Berlin Heidelberg.
Vanhoucke, M. (2014) Integrated Project Management and Control: First Comes the Theory, then the Practice. Springer International Publishing Switzerland.
On vignette package there is more information with examples about:
Critical Path Method Package criticalpath.
How to create a schedule:
Add activities and relations together to an schedule.
Add activities to a schedule.
Add relations to a schedule.
Create a schedule object from data frames.
How to get schedule information:
Title, Reference and Schedule Duration.
How to get activities properties:
Activity Properties.
Gantt Matrix.
How to change activities duration:
Change Activities Duration.
How to get relations properties:
Relation Properties
Successors and Predecessors.
How to get topological properties:
Topological Indicators.