def to_pert_graph(self):
"""Build PertGraph from nodes table (creating dummy activities for parallel activities)"""
pm_graph = pert.PertMultigraph()
for i in range(self.num_real_activities):
pm_graph.add_arc((self.node_list[i][0], self.node_list[i][1]),
(self.activity_names[i], False))
for i in range(self.num_real_activities, len(self.node_list)):
pm_graph.add_arc((self.node_list[i][0], self.node_list[i][1]),
(self.activity_names[i], True))
return pm_graph.to_directed_graph()
def cohen_sadeh(prelations):
"""
Build graph PERT using Cohen-Sadeh algorithm
Note: the original algorithm does not consider parallel activities (creates a multigraph)
prelations = {'activity': ['predecesor1', 'predecesor2'...}
return graph pert.Pert()
"""
# Adaptation to avoid multiple end nodes
successors = graph.reversed_prelation_table(prelations)
end_act = graph.ending_activities(successors)
#Step 1. Construct work table with Immediate Predecessors
Columns = namedlist.namedlist('Columns', ['pre', 'blocked', 'dummy', 'suc', 'start_node', 'end_node'])
# [0 Predecesors, 1 Blocked, 2 Dummy, 3 Successors, 4 Start node, 5 End node]
# Blocked = (False or Activity with same precedents)
work_table = {}
for act, predecessors in prelations.items():
work_table[act] = Columns(set(predecessors), False, False, None, None, None)
# print "\n--- Step 1 ---"
# __print_work_table(work_table)
#Step 2. Identify Identical Precedence Constraint of Diferent Activities
visited_pred = {}
for act, columns in work_table.items():
pred = frozenset(columns.pre)
if pred not in visited_pred:
visited_pred[pred] = act
else:
columns.blocked = visited_pred[pred]
# print "\n--- Step 2 ---"
# __print_work_table(work_table)
#Step 3. Identify Necessary Dummy Arcs
dups = set()
visited_act = set()
for columns in work_table.values():
if not columns.blocked:
for act in columns.pre:
if act in visited_act:
dups.add(act)
visited_act.add(act)
# print "\n--- Step 3.1 ---"
# print dups
#Step 3.2, 3.3 and 4. Create rows and information for Dummy Arcs
dummy_counter = collections.Counter()
for _, columns in work_table.items():
# Avoid blocked
if not columns.blocked:
predecessors = columns.pre
if len(predecessors) > 1:
for pre in list(predecessors):
if pre in dups:
predecessors.remove(pre)
dummy_name = pre + '-d' + str(dummy_counter[pre])
dummy_counter[pre] += 1
predecessors.add(dummy_name)
work_table[dummy_name] = Columns(set([pre]), False, True, None, None, None)
# print "\n--- Step 4 ---"
# __print_work_table(work_table)
#Step 5. Creating nodes
node = 0 # instead of 0, can start at 100 to avoid confusion with activities named with numbers when debugging
for act, columns in work_table.items():
if not columns.dummy and not columns.blocked:
columns.start_node = node
node += 1
# print "\n--- Step 5a ---"
# __print_work_table(work_table)
for act, columns in work_table.items():
if not columns.dummy and columns.blocked:
columns.start_node = work_table[columns.blocked].start_node
# print "\n--- Step 5b ---"
# __print_work_table(work_table)
#Step 6. Associate activities with their end nodes
# (a) find one non-dummy successor for each activity
for act, columns in work_table.items():
for suc, suc_columns in work_table.items():
if not suc_columns.dummy and not suc_columns.blocked:
if act in suc_columns.pre:
columns.suc = suc
break
# print "\n--- Step 6a ---"
# __print_work_table(work_table)
# (b) find end nodes
graph_end_node = node # Reserve one node for graph end
node += 1
for act, columns in work_table.items():
suc = columns.suc
if suc:
columns.end_node = work_table[suc].start_node
else:
# Create needed end nodes, avoiding multiple graph end nodes (adaptation)
if act in end_act:
columns.end_node = graph_end_node
else:
columns.end_node = node
node += 1
# print "\n--- Step 6b ---"
# __print_work_table(work_table)
#Step 7. Associate dummy arcs with start nodes
for act, columns in work_table.items():
if columns.dummy:
pred = iter(columns.pre).next()
start_node = work_table[pred].end_node
columns.start_node = start_node
# print "\n--- Step 7 ---"
# __print_work_table(work_table)
#Step 8. Generate the graph
pm_graph = pert.PertMultigraph()
for act, columns in work_table.items():
_, _, dummy, _, start, end = columns
pm_graph.add_arc((start, end), (act, dummy))
p_graph = pm_graph.to_directed_graph()
return p_graph.renumerar()
def sysloOptimal(prelations):
"""
Build a PERT graph using Syslo algorithm
return p_graph pert.PertMultigraph()
"""
# Adaptation to avoid multiple end nodes
successors = graph.reversed_prelation_table(prelations)
end_act = graph.ending_activities(successors)
#Kahn1962.check_cycles(successors)
prela = successors.copy()
Columns = namedlist.namedlist('Columns', ['pre', 'blocked', 'dummy', 'suc', 'start_node', 'end_node'])
# [0 Predecesors, 1 Blocked, 2 Dummy, 3 Successors, 4 Start node, 5 End node]
# Blocked = (False or Activity with same precedents)
#Step 0.
grafo = {}
alt = graph.successors2precedents(successors)
grafo = graph.successors2precedents(syslo_table.syslo(prela, grafo, alt))
#Step 1. Save the new prelation table in a work table
work_table = {}
for act, pre in grafo.items():
if not act in prelations:
work_table[act] = Columns(pre, False, True, None, None, None)
else:
work_table[act] = Columns(pre, False, False, None, None, None)
#Step 2. Identify Dummy Activities And Identical Precedence Constraint of Diferent Activities
visited_pred = {}
for act, columns in work_table.items():
pred = frozenset(columns.pre)
if pred not in visited_pred:
visited_pred[pred] = act
else:
columns.blocked = visited_pred[pred]
#Step 3. Creating nodes
# (a) find start nodes
node = 0 # instead of 0, can start at 100 to avoid confusion with activities named with numbers when debugging
for act, columns in work_table.items():
if not columns.blocked:
columns.start_node = node
node += 1
if columns.blocked:
columns.start_node = work_table[columns.blocked].start_node
# Associate activities with their end nodes
for suc, suc_columns in work_table.items():
if not suc_columns.blocked:
if act in suc_columns.pre:
columns.suc = suc
break
# (b) find end nodes
graph_end_node = node # Reserve one node for graph end
node += 1
for act, columns in work_table.items():
suc = columns.suc
if suc:
columns.end_node = work_table[suc].start_node
else:
# Create needed end nodes, avoiding multiple graph end nodes (adaptation)
if act in end_act:
columns.end_node = graph_end_node
else:
columns.end_node = node
node += 1
# Step 4. Remove redundancy of dummy activities
vis = []
for act, columns in work_table.items():
if columns.dummy == False:
for q in work_table[act].pre:
for w in work_table[act].pre:
if q in work_table and w in work_table:
if q != w and work_table[q].pre == work_table[w].pre and work_table[q].dummy==True and work_table[w].dummy==True:
if w not in vis:
del work_table[w]
vis.append(q)
#Step 5. Generate the graph
pm_graph = pert.PertMultigraph()
for act, columns in work_table.items():
_, _, dummy, _, start, end = columns
pm_graph.add_arc((start, end), (act, dummy))
p_graph = pm_graph.to_directed_graph()
return p_graph
return p_graph
def sysloPolynomial(prelations):
# Adaptation to avoid multiple end nodes
successors = graph.reversed_prelation_table(prelations)
end_act = graph.ending_activities(successors)
#Step 0. Construct work table with Immediate Predecessors
Columns = namedlist.namedlist('Columns', ['pre', 'blocked', 'dummy', 'suc', 'start_node', 'end_node'])
# [0 Predecesors, 1 Blocked, 2 Dummy, 3 Successors, 4 Start node, 5 End node]
# Blocked = (False or Activity with same precedents)
#Step 1. Create the improper covers
work_table_pol = makeCover(prelations, successors)
# Step 2. Syslo Polynomial algorithm
final = successors.copy()
visited = []
for act, pred in prelations.items():
for v in pred:
for u in pred:
if u != v and successors[v] != successors[u] and act not in visited:
# Find activity in the improper cover table
for key, value in work_table_pol.items():
if act in value.w:
w = value.w
# Find each row that belongs to the predecessors of activity
for key, value in work_table_pol.items():
if set(value.u).issubset(prelations[act]) and value.u:
vertex = set(value.u).pop()
# Compare successors of a row with the improper cover of the activity
if successors[vertex] != w:
for q in value.u:
if final.has_key(q):
final[q] = list((set(final[q]) - set(w) | set([str(vertex) + separator + str(act)])) - set([act]))
else:
final[q] = list(set(successors[q]) - set(w) | set([str(vertex) + separator + str(act)]))
final[str(vertex) + separator + str(act)] = [act]
for l in w:
visited.append(l)
final = graph.successors2precedents(final)
work_table = {}
for act, pred in final.items():
work_table[act] = Columns(pred, False, False, None, None, None)
if act not in prelations:
work_table[act].dummy = True
#Step 3. Identify Dummy Activities And Identical Precedence Constraint of Diferent Activities
visited_pred = {}
for act, columns in work_table.items():
pred = frozenset(columns.pre)
if pred not in visited_pred:
visited_pred[pred] = act
else:
columns.blocked = visited_pred[pred]
#Step 4. Creating nodes
# (a) find start nodes
node = 0 # instead of 0, can start at 100 to avoid confusion with activities named with numbers when debugging
for act, columns in work_table.items():
if not columns.blocked:
columns.start_node = node
node += 1
if columns.blocked:
columns.start_node = work_table[columns.blocked].start_node
# Associate activities with their end nodes
for suc, suc_columns in work_table.items():
if not suc_columns.blocked:
if act in suc_columns.pre:
columns.suc = suc
break
# (b) find end nodes
graph_end_node = node # Reserve one node for graph end
node += 1
pm_graph = pert.PertMultigraph()
for act, columns in work_table.items():
suc = columns.suc
if suc:
columns.end_node = work_table[suc].start_node
else:
# Create needed end nodes, avoiding multiple graph end nodes (adaptation)
if act in end_act:
columns.end_node = node
else:
columns.end_node = graph_end_node
node += 1
# Generate the graph
_, _, dummy, _, start, end = columns
pm_graph.add_arc((start, end), (act, dummy))
p_graph = pm_graph.to_directed_graph()
return p_graph
def mouhoub(prelations):
"""
Build a PERT graph using Mouhoub algorithm
prelations = {'activity': ['predecesor1', 'predecesor2'...}
return p_graph pert.PertMultigraph()
"""
Columns = namedlist.namedlist('Columns', ['pre', 'su', 'blocked', 'dummy', 'suc', 'start_node', 'end_node', 'aux'])
# [0 Predecesors, 1 Successors, 2 Blocked, 3 Dummy, 4 Blocked successor, 5 Start node, 6 End node, 7 Auxiliar ]
# Blocked = (False or Activity with same precedents)
# Adaptation to avoid multiple end nodes
successors = graph.reversed_prelation_table(prelations)
successors_copy = graph.reversed_prelation_table(prelations.copy())
end_act = graph.ending_activities(successors)
# Step 0. Remove Z Configuration. Update the prelation table in complete_bipartite dictionary
complete_bipartite = successors
complete_bipartite.update(zConfiguration.zconf(successors))
# STEPS TO BUILD THE PERT GRAPH
#Step 1. Save the prelations in the work table
complete_bipartite = graph.successors2precedents(complete_bipartite)
work_table = {}
for act, sucesores in complete_bipartite.items():
work_table[act] = Columns(set(sucesores), successors[act], None, False, None, None, None, None)
if act not in prelations:
work_table[act].dummy = True
#Step 2. Identify Identical Precedence Constraint of Diferent Activities
visited_pred = {}
for act, columns in work_table.items():
pred = frozenset(columns.pre)
if pred not in visited_pred:
visited_pred[pred] = act
else:
columns.blocked = visited_pred[pred]
#Step 3. Creating nodes
# (a) Find start nodes
node = 0 # instead of 0, can start at 100 to avoid confusion with activities named with numbers when debugging
for act, columns in work_table.items():
if not columns.blocked:
columns.start_node = node
node += 1
if columns.blocked:
columns.start_node = work_table[columns.blocked].start_node
# Associate activities with their end nodes
for suc, suc_columns in work_table.items():
if not suc_columns.blocked:
if act in suc_columns.pre:
columns.suc = suc
break
# (b) Find end nodes
graph_end_node = node # Reserve one node for graph end
node += 1
for act, columns in work_table.items():
suc = columns.suc
if suc:
columns.end_node = work_table[suc].start_node
else:
# Create needed end nodes, avoiding multiple graph end nodes (adaptation)
if act in end_act:
columns.end_node = graph_end_node
else:
columns.end_node = node
node += 1
#Step 4. MOUHOUB algorithm rules to remove extra dummy activities
mouhoubRules.rule_1(successors_copy, work_table)
G2 = mouhoubRules.rule_2(prelations, work_table)
G3 = mouhoubRules.rule_3(G2, work_table)
G4 = mouhoubRules.rule_4(G3, work_table)
G5_6 = mouhoubRules.rule_5_6(successors_copy, work_table, G4)
G3a = mouhoubRules.rule_3(G5_6, work_table)
G4a = mouhoubRules.rule_4(G3a, work_table)
G7 = mouhoubRules.rule_7(successors_copy, successors, G4a, node)
work_table_final = {}
for act, sucesores in G7.items():
work_table_final[act] = Columns([], [], [], sucesores.dummy, sucesores.suc, sucesores.start_node, sucesores.end_node, [])
#Step 5. Delete Dummy Cycles
for act, sucesores in work_table_final.items():
for act2, sucesores2 in work_table_final.items():
if act != act2:
if sucesores.end_node == sucesores2.end_node and sucesores.start_node == sucesores2.start_node:
if act not in successors:
del work_table_final[act]
#Step 6. Generate the graph
pm_graph = pert.PertMultigraph()
for act, columns in work_table_final.items():
_, _, _, dummy, _, start, end, _ = columns
pm_graph.add_arc((start, end), (act, dummy))
p_graph = pm_graph.to_directed_graph()
return p_graph