public static double ComputeEarliestStartTime(Task t, Schedule schedule) {
ScheduledTask previousTask = schedule.GetLastScheduledTaskForJobNr(t.JobNr);
Resource affectedResource = schedule.Resources[t.ResourceNr];
double lastMachineEndTime = affectedResource.TotalDuration;
double previousJobTaskEndTime = 0;
if (previousTask != null)
previousJobTaskEndTime = previousTask.EndTime;
return Math.Max(previousJobTaskEndTime, lastMachineEndTime);
}
public static Schedule Apply(int jobs, int resources, PWREncoding pwr, ItemList<Job> jobData) {
var resultingSchedule = new Schedule(jobData[0].Tasks.Count);
foreach (int jobNr in pwr.PermutationWithRepetition) {
int i = 0;
while (jobData[jobNr].Tasks[i].IsScheduled) i++;
Task currentTask = jobData[jobNr].Tasks[i];
double startTime = GTAlgorithmUtils.ComputeEarliestStartTime(currentTask, resultingSchedule);
currentTask.IsScheduled = true;
resultingSchedule.ScheduleTask(currentTask.ResourceNr, startTime, currentTask.Duration, currentTask.JobNr);
}
return resultingSchedule;
}
public static ItemList<Task> GetConflictSetForTask(Task conflictedTask, ItemList<Task> earliestTasksList, ItemList<Job> jobData, Schedule schedule) {
ItemList<Task> result = new ItemList<Task>();
double conflictedCompletionTime = ComputeEarliestCompletionTime(conflictedTask, schedule);
result.Add(conflictedTask);
foreach (Task t in earliestTasksList) {
if (t.ResourceNr == conflictedTask.ResourceNr) {
if (ComputeEarliestStartTime(t, schedule) < conflictedCompletionTime)
result.Add(t);
}
}
return result;
}
//earliest start time
private Task ESTRule(ItemList<Task> tasks, Schedule schedule) {
Task currentResult = RandomRule(tasks);
double currentEST = double.MaxValue;
foreach (Task t in tasks) {
double est = GTAlgorithmUtils.ComputeEarliestStartTime(t, schedule);
if (est < currentEST) {
currentEST = est;
currentResult = t;
}
}
return currentResult;
}
public static Task GetTaskWithMinimalEC(ItemList<Task> earliestTasksList, Schedule schedule) {
double minEct = double.MaxValue;
Task result = null;
foreach (Task t in earliestTasksList) {
double ect = ComputeEarliestCompletionTime(t, schedule);
if (ect < minEct) {
result = t;
minEct = ect;
}
}
return result;
}
public override Schedule CreateScheduleFromEncoding(IScheduleEncoding encoding) {
var solution = encoding as PWREncoding;
if (solution == null) throw new InvalidOperationException("Encoding is not of type PWREncoding");
var jobs = (ItemList<Job>)JobDataParameter.ActualValue.Clone();
var resultingSchedule = new Schedule(jobs[0].Tasks.Count);
foreach (int jobNr in solution.PermutationWithRepetition) {
int i = 0;
while (jobs[jobNr].Tasks[i].IsScheduled) i++;
Task currentTask = jobs[jobNr].Tasks[i];
double startTime = GTAlgorithmUtils.ComputeEarliestStartTime(currentTask, resultingSchedule);
currentTask.IsScheduled = true;
resultingSchedule.ScheduleTask(currentTask.ResourceNr, startTime, currentTask.Duration, currentTask.JobNr);
}
return resultingSchedule;
}
protected override double Evaluate(Schedule schedule) {
return GetMeanTardiness(schedule, JobDataParameter.ActualValue);
}
public static double GetMeanTardiness(Schedule schedule, ItemList<Job> jobData) {
return schedule.Resources
.Select(r => Math.Max(0, r.Tasks.Last().EndTime - jobData[r.Tasks.Last().JobNr].DueDate))
.Average();
}
private Schedule(Schedule original, Cloner cloner)
: base(original, cloner) {
this.Resources = cloner.Clone(original.Resources);
this.Quality = cloner.Clone(original.Quality);
this.lastScheduledTaskOfJob = new Dictionary<int, ScheduledTask>(original.lastScheduledTaskOfJob);
}
protected abstract double Evaluate(Schedule schedule);
public static double ComputeEarliestCompletionTime(Task t, Schedule schedule) {
return ComputeEarliestStartTime(t, schedule) + t.Duration;
}
public override Schedule CreateScheduleFromEncoding(IScheduleEncoding encoding) {
var solution = encoding as PRVEncoding;
if (solution == null) throw new InvalidOperationException("Encoding is not of type PWREncoding");
var jobs = (ItemList<Job>)JobDataParameter.ActualValue.Clone();
var resultingSchedule = new Schedule(jobs[0].Tasks.Count);
//Reset scheduled tasks in result
foreach (Job j in jobs) {
foreach (Task t in j.Tasks) {
t.IsScheduled = false;
}
}
//GT-Algorithm
//STEP 0 - Compute a list of "earliest operations"
ItemList<Task> earliestTasksList = GTAlgorithmUtils.GetEarliestNotScheduledTasks(jobs);
//int currentDecisionIndex = 0;
while (earliestTasksList.Count > 0) {
//STEP 1 - Get earliest not scheduled operation with minimal earliest completing time
Task minimal = GTAlgorithmUtils.GetTaskWithMinimalEC(earliestTasksList, resultingSchedule);
//STEP 2 - Compute a conflict set of all operations that can be scheduled on the machine the previously selected operation runs on
ItemList<Task> conflictSet = GTAlgorithmUtils.GetConflictSetForTask(minimal, earliestTasksList, jobs, resultingSchedule);
//STEP 3 - Select an operation from the conflict set (various methods depending on how the algorithm should work..)
//Task selectedTask = SelectTaskFromConflictSet(conflictSet, solution.PriorityRulesVector [currentDecisionIndex++], solution.NrOfRules.Value);
Task selectedTask = SelectTaskFromConflictSet(conflictSet, solution.PriorityRulesVector[minimal.JobNr], solution.NrOfRules.Value, resultingSchedule, jobs);
//STEP 4 - Adding the selected operation to the current schedule
selectedTask.IsScheduled = true;
double startTime = GTAlgorithmUtils.ComputeEarliestStartTime(selectedTask, resultingSchedule);
resultingSchedule.ScheduleTask(selectedTask.ResourceNr, startTime, selectedTask.Duration, selectedTask.JobNr);
//STEP 5 - Back to STEP 1
earliestTasksList = GTAlgorithmUtils.GetEarliestNotScheduledTasks(jobs);
}
return resultingSchedule;
}
private Task SelectTaskFromConflictSet(ItemList<Task> conflictSet, int ruleIndex, int nrOfRules, Schedule schedule, ItemList<Job> jobs) {
if (conflictSet.Count == 1)
return conflictSet[0];
ruleIndex = ruleIndex % nrOfRules;
switch (ruleIndex) {
case 0: return FILORule(conflictSet);
case 1: return ESTRule(conflictSet, schedule);
case 2: return SPTRule(conflictSet);
case 3: return LPTRule(conflictSet);
case 4: return MWRRule(conflictSet, jobs);
case 5: return LWRRule(conflictSet, jobs);
case 6: return MORRule(conflictSet, jobs);
case 7: return LORRule(conflictSet, jobs);
case 8: return FIFORule(conflictSet);
case 9: return RandomRule(conflictSet);
default: return RandomRule(conflictSet);
}
}
public Schedule CreateScheduleFromEncoding(JSMEncoding solution, ItemList<Job> jobData) {
ItemList<Permutation> jobSequenceMatrix = solution.JobSequenceMatrix;
var jobs = (ItemList<Job>)jobData.Clone();
var resultingSchedule = new Schedule(jobs[0].Tasks.Count);
//Reset scheduled tasks in result
foreach (Job j in jobs) {
foreach (Task t in j.Tasks) {
t.IsScheduled = false;
}
}
//GT-Algorithm
//STEP 0 - Compute a list of "earliest operations"
ItemList<Task> earliestTasksList = GTAlgorithmUtils.GetEarliestNotScheduledTasks(jobs);
while (earliestTasksList.Count > 0) {
//STEP 1 - Get earliest not scheduled operation with minimal earliest completing time
Task minimal = GTAlgorithmUtils.GetTaskWithMinimalEC(earliestTasksList, resultingSchedule);
int conflictedResourceNr = minimal.ResourceNr;
Resource conflictedResource = resultingSchedule.Resources[conflictedResourceNr];
//STEP 2 - Compute a conflict set of all operations that can be scheduled on the conflicted resource
ItemList<Task> conflictSet = GTAlgorithmUtils.GetConflictSetForTask(minimal, earliestTasksList, jobs, resultingSchedule);
//STEP 3 - Select a task from the conflict set
int progressOnResource = conflictedResource.Tasks.Count;
Task selectedTask = SelectTaskFromConflictSet(conflictedResourceNr, progressOnResource, conflictSet, jobSequenceMatrix);
//STEP 4 - Add the selected task to the current schedule
selectedTask.IsScheduled = true;
double startTime = GTAlgorithmUtils.ComputeEarliestStartTime(selectedTask, resultingSchedule);
resultingSchedule.ScheduleTask(selectedTask.ResourceNr, startTime, selectedTask.Duration, selectedTask.JobNr);
//STEP 5 - Back to STEP 1
earliestTasksList = GTAlgorithmUtils.GetEarliestNotScheduledTasks(jobs);
}
return resultingSchedule;
}
protected override double Evaluate(Schedule schedule) {
return GetMakespan(schedule);
}
public static double GetMakespan(Schedule schedule) {
return schedule.Resources.Select(r => r.TotalDuration).Max();
}
