void SolverMRP::solve(const BufferInfinite* b, void* v)
{
SolverMRPdata* data = static_cast<SolverMRPdata*>(v);
// Call the user exit
if (userexit_buffer) userexit_buffer.call(b, PythonData(data->constrainedPlanning));
// Message
if (data->getSolver()->getLogLevel()>1)
logger << indent(b->getLevel()) << " Infinite buffer '" << b << "' is asked: "
<< data->state->q_qty << " " << data->state->q_date << endl;
// Reply whatever is requested, regardless of date, quantity or supply.
// The demand is not propagated upstream either.
data->state->a_qty = data->state->q_qty;
data->state->a_date = data->state->q_date;
if (b->getItem())
data->state->a_cost += data->state->q_qty * b->getItem()->getPrice();
// Message
if (data->getSolver()->getLogLevel()>1)
logger << indent(b->getLevel()) << " Infinite buffer '" << b << "' answers: "
<< data->state->a_qty << " " << data->state->a_date << " "
<< data->state->a_cost << " " << data->state->a_penalty << endl;
}
DECLARE_EXPORT void SolverMRP::solve(const Flow* fl, void* v) // @todo implement search mode
{
// Note: This method is only called for consuming flows and for the leading
// flow of an alternate group. See SolverMRP::checkOperation
SolverMRPdata* data = static_cast<SolverMRPdata*>(v);
if (fl->hasAlternates())
{
// CASE I: It is an alternate flow.
// We ask each alternate flow in order of priority till we find a flow
// that has a non-zero reply.
// 1) collect a list of alternates
list<const Flow*> thealternates;
const Flow *x = fl->hasAlternates() ? fl : fl->getAlternate();
for (Operation::flowlist::const_iterator i = fl->getOperation()->getFlows().begin();
i != fl->getOperation()->getFlows().end(); ++i)
if ((i->getAlternate() == x || &*i == x)
&& i->getEffective().within(data->state->q_flowplan->getDate()))
thealternates.push_front(&*i);
// 2) Sort the list
thealternates.sort(sortFlow);
// 3) Control the planning mode
bool originalPlanningMode = data->constrainedPlanning;
data->constrainedPlanning = true;
const Flow *firstAlternate = NULL;
double firstQuantity = 0.0;
// Remember the top constraint
bool originalLogConstraints = data->logConstraints;
//Problem* topConstraint = data->planningDemand->getConstraints().top();
// 4) Loop through the alternates till we find a non-zero reply
Date min_next_date(Date::infiniteFuture);
double ask_qty;
FlowPlan *flplan = data->state->q_flowplan;
for (list<const Flow*>::const_iterator i = thealternates.begin();
i != thealternates.end();)
{
const Flow *curflow = *i;
data->state->q_flowplan = flplan; // because q_flowplan can change
// 4a) Switch to this flow
if (data->state->q_flowplan->getFlow() != curflow)
data->state->q_flowplan->setFlow(curflow);
// 4b) Call the Python user exit if there is one
if (userexit_flow)
{
PythonObject result = userexit_flow.call(data->state->q_flowplan, PythonObject(data->constrainedPlanning));
if (!result.getBool())
{
// Return value is false, alternate rejected
if (data->getSolver()->getLogLevel()>1)
logger << indent(curflow->getOperation()->getLevel())
<< " User exit disallows consumption from '"
<< (*i)->getBuffer()->getName() << "'" << endl;
// Move to the next alternate
if (++i != thealternates.end() && data->getSolver()->getLogLevel()>1)
logger << indent(curflow->getOperation()->getLevel()) << " Alternate flow switches from '"
<< curflow->getBuffer()->getName() << "' to '"
<< (*i)->getBuffer()->getName() << "'" << endl;
continue;
}
}
// Remember the first alternate
if (!firstAlternate)
{
firstAlternate = *i;
firstQuantity = data->state->q_flowplan->getQuantity();
}
// Constraint tracking
if (*i != firstAlternate)
// Only enabled on first alternate
data->logConstraints = false;
else
// Keep track of constraints, if enabled
data->logConstraints = originalLogConstraints;
// 4c) Ask the buffer
data->state->q_qty = ask_qty = - data->state->q_flowplan->getQuantity();
data->state->q_date = data->state->q_flowplan->getDate();
CommandManager::Bookmark* topcommand = data->setBookmark();
curflow->getBuffer()->solve(*this,data);
// 4d) A positive reply: exit the loop
if (data->state->a_qty > ROUNDING_ERROR)
{
// Update the opplan, which is required to (1) update the flowplans
// and to (2) take care of lot sizing constraints of this operation.
if (data->state->a_qty < ask_qty - ROUNDING_ERROR)
{
flplan->setQuantity(-data->state->a_qty, true);
data->state->a_qty = -flplan->getQuantity();
}
if (data->state->a_qty > ROUNDING_ERROR)
{
data->constrainedPlanning = originalPlanningMode;
data->logConstraints = originalLogConstraints;
return;
}
}
// 4e) Undo the plan on the alternate
data->rollback(topcommand);
// 4f) Prepare for the next alternate
if (data->state->a_date < min_next_date)
min_next_date = data->state->a_date;
if (++i != thealternates.end() && data->getSolver()->getLogLevel()>1)
logger << indent(curflow->getOperation()->getLevel()) << " Alternate flow switches from '"
<< curflow->getBuffer()->getName() << "' to '"
<< (*i)->getBuffer()->getName() << "'" << endl;
}
// 5) No reply found, all alternates are infeasible
if (!originalPlanningMode)
{
assert(firstAlternate);
// Unconstrained plan: Plan on the primary alternate
// Switch to this flow
if (flplan->getFlow() != firstAlternate)
flplan->setFlow(firstAlternate);
// Message
if (data->getSolver()->getLogLevel()>1)
logger << indent(fl->getOperation()->getLevel())
<< " Alternate flow plans unconstrained on alternate '"
<< firstAlternate->getBuffer()->getName() << "'" << endl;
// Plan unconstrained
data->constrainedPlanning = false;
data->state->q_flowplan = flplan; // because q_flowplan can change
flplan->setQuantity(firstQuantity, true);
data->state->q_qty = ask_qty = - flplan->getQuantity();
data->state->q_date = flplan->getDate();
firstAlternate->getBuffer()->solve(*this,data);
data->state->a_qty = -flplan->getQuantity();
// Restore original planning mode
data->constrainedPlanning = originalPlanningMode;
}
else
{
// Constrained plan: Return 0
data->state->a_date = min_next_date;
data->state->a_qty = 0;
if (data->getSolver()->getLogLevel()>1)
logger << indent(fl->getOperation()->getLevel()) <<
" Alternate flow doesn't find supply on any alternate : "
<< data->state->a_qty << " " << data->state->a_date << endl;
}
}
else
{
// CASE II: Not an alternate flow.
// In this case, this method is passing control on to the buffer.
data->state->q_qty = - data->state->q_flowplan->getQuantity();
data->state->q_date = data->state->q_flowplan->getDate();
if (data->state->q_qty != 0.0)
{
fl->getBuffer()->solve(*this,data);
if (data->state->a_date > fl->getEffective().getEnd())
{
// The reply date must be less than the effectivity end date: after
// that date the flow in question won't consume any material any more.
if (data->getSolver()->getLogLevel()>1
&& data->state->a_qty < ROUNDING_ERROR)
logger << indent(fl->getBuffer()->getLevel()) << " Buffer '"
<< fl->getBuffer()->getName() << "' answer date is adjusted to "
<< fl->getEffective().getEnd()
<< " because of a date effective flow" << endl;
data->state->a_date = fl->getEffective().getEnd();
}
}
else
{
// It's a zero quantity flowplan.
// E.g. because it is not effective.
data->state->a_date = data->state->q_date;
data->state->a_qty = 0.0;
}
}
}
DECLARE_EXPORT void SolverMRP::solve(const Demand* l, void* v)
{
// Set a bookmark at the current command
SolverMRPdata* data = static_cast<SolverMRPdata*>(v);
CommandManager::Bookmark* topcommand = data->setBookmark();
// Create a state stack
State* mystate = data->state;
data->push();
try
{
// Call the user exit
if (userexit_demand) userexit_demand.call(l, PythonData(data->constrainedPlanning));
short loglevel = data->getSolver()->getLogLevel();
// Note: This solver method does not push/pop states on the stack.
// We continue to work on the top element of the stack.
// Message
if (loglevel>0)
{
logger << "Planning demand '" << l->getName() << "' (" << l->getPriority()
<< ", " << l->getDue() << ", " << l->getQuantity() << ")";
if (!data->constrainedPlanning || !data->getSolver()->isConstrained())
logger << " in unconstrained mode";
logger << endl;
}
// Unattach previous delivery operationplans, if required.
if (data->getSolver()->getErasePreviousFirst())
{
// Locked operationplans will NOT be deleted, and a part of the demand can
// still remain planned.
const_cast<Demand*>(l)->deleteOperationPlans(false, data);
// Empty constraint list
const_cast<Demand*>(l)->getConstraints().clear();
}
// Track constraints or not
data->logConstraints = (getPlanType() == 1);
// Determine the quantity to be planned and the date for the planning loop
double plan_qty = l->getQuantity() - l->getPlannedQuantity();
Date plan_date = l->getDue();
if (plan_qty < ROUNDING_ERROR || plan_date == Date::infiniteFuture)
{
if (loglevel>0) logger << " Nothing to be planned." << endl;
data->pop();
return;
}
if (plan_qty < l->getMinShipment()) plan_qty = l->getMinShipment();
// Temporary values to store the 'best-reply' so far
double best_q_qty = 0.0, best_a_qty = 0.0;
Date best_q_date;
// Select delivery operation
Operation* deliveryoper = l->getDeliveryOperation();
// Handle invalid or missing delivery operations
{
string problemtext = string("Demand '") + l->getName() + "' has no delivery operation";
Problem::const_iterator j = Problem::begin(const_cast<Demand*>(l), false);
while (j!=Problem::end())
{
if (&(j->getType()) == ProblemInvalidData::metadata
&& j->getDescription() == problemtext)
break;
++j;
}
if (!deliveryoper)
{
// Create a problem
if (j == Problem::end())
new ProblemInvalidData(const_cast<Demand*>(l), problemtext, "demand",
l->getDue(), l->getDue(), l->getQuantity());
// Abort planning of this demand
throw DataException("Demand '" + l->getName() + "' can't be planned");
}
else
// Remove problem that may already exist
delete &*j;
}
// Planning loop
do
{
// Message
if (loglevel>0)
logger << "Demand '" << l << "' asks: "
<< plan_qty << " " << plan_date << endl;
// Store the last command in the list, in order to undo the following
// commands if required.
CommandManager::Bookmark* topcommand = data->setBookmark();
// Plan the demand by asking the delivery operation to plan
double q_qty = plan_qty;
data->state->curBuffer = NULL;
data->state->q_qty = plan_qty;
data->state->q_date = plan_date;
data->planningDemand = const_cast<Demand*>(l);
data->state->curDemand = const_cast<Demand*>(l);
data->state->curOwnerOpplan = NULL;
deliveryoper->solve(*this,v);
Date next_date = data->state->a_date;
if (data->state->a_qty < ROUNDING_ERROR
&& plan_qty > l->getMinShipment() && l->getMinShipment() > 0)
{
bool originalLogConstraints = data->logConstraints;
data->logConstraints = false;
try
{
// The full asked quantity is not possible.
// Try with the minimum shipment quantity.
if (loglevel>1)
logger << "Demand '" << l << "' tries planning minimum quantity " << l->getMinShipment() << endl;
data->rollback(topcommand);
data->state->curBuffer = NULL;
data->state->q_qty = l->getMinShipment();
data->state->q_date = plan_date;
data->state->curDemand = const_cast<Demand*>(l);
deliveryoper->solve(*this,v);
if (data->state->a_date < next_date)
next_date = data->state->a_date;
if (data->state->a_qty > ROUNDING_ERROR)
{
// The minimum shipment quantity is feasible.
// Now try iteratively different quantities to find the best we can do.
double min_qty = l->getMinShipment();
double max_qty = plan_qty;
double delta = fabs(max_qty - min_qty);
while (delta > data->getSolver()->getIterationAccuracy() * l->getQuantity()
&& delta > data->getSolver()->getIterationThreshold())
{
// Note: we're kind of assuming that the demand is an integer value here.
double new_qty = floor((min_qty + max_qty) / 2);
if (new_qty == min_qty)
{
// Required to avoid an infinite loop on the same value...
new_qty += 1;
if (new_qty > max_qty) break;
}
if (loglevel>0)
logger << "Demand '" << l << "' tries planning a different quantity " << new_qty << endl;
data->rollback(topcommand);
data->state->curBuffer = NULL;
data->state->q_qty = new_qty;
data->state->q_date = plan_date;
data->state->curDemand = const_cast<Demand*>(l);
deliveryoper->solve(*this,v);
if (data->state->a_date < next_date)
next_date = data->state->a_date;
if (data->state->a_qty > ROUNDING_ERROR)
// Too small: new min
min_qty = new_qty;
else
// Too big: new max
max_qty = new_qty;
delta = fabs(max_qty - min_qty);
}
q_qty = min_qty; // q_qty is the biggest Q quantity giving a positive reply
if (data->state->a_qty <= ROUNDING_ERROR)
{
if (loglevel>0)
logger << "Demand '" << l << "' restores plan for quantity " << min_qty << endl;
// Restore the last feasible plan
data->rollback(topcommand);
data->state->curBuffer = NULL;
data->state->q_qty = min_qty;
data->state->q_date = plan_date;
data->state->curDemand = const_cast<Demand*>(l);
deliveryoper->solve(*this,v);
}
}
}
catch (...)
{
data->logConstraints = originalLogConstraints;
throw;
}
data->logConstraints = originalLogConstraints;
}
// Message
if (loglevel>0)
logger << "Demand '" << l << "' gets answer: "
<< data->state->a_qty << " " << next_date << " "
<< data->state->a_cost << " " << data->state->a_penalty << endl;
// Update the date to plan in the next loop
Date copy_plan_date = plan_date;
// Compare the planned quantity with the minimum allowed shipment quantity
// We don't accept the answer in case:
// 1) Nothing is planned
// 2) The planned quantity is less than the minimum shipment quantity
// 3) The remaining quantity after accepting this answer is less than
// the minimum quantity.
if (data->state->a_qty < ROUNDING_ERROR
|| data->state->a_qty + ROUNDING_ERROR < l->getMinShipment()
|| (plan_qty - data->state->a_qty < l->getMinShipment()
&& fabs(plan_qty - data->state->a_qty) > ROUNDING_ERROR))
{
if (plan_qty - data->state->a_qty < l->getMinShipment()
&& data->state->a_qty + ROUNDING_ERROR >= l->getMinShipment()
&& data->state->a_qty > best_a_qty )
{
// The remaining quantity after accepting this answer is less than
// the minimum quantity. Therefore, we delay accepting it now, but
// still keep track of this best offer.
best_a_qty = data->state->a_qty;
best_q_qty = q_qty;
best_q_date = plan_date;
}
// Delete operationplans - Undo all changes
data->rollback(topcommand);
// Set the ask date for the next pass through the loop
if (next_date <= copy_plan_date
|| (!data->getSolver()->getAllowSplits() && data->state->a_qty > ROUNDING_ERROR)
|| (data->state->a_qty > ROUNDING_ERROR && plan_qty - data->state->a_qty < l->getMinShipment()
&& plan_qty - data->state->a_qty > ROUNDING_ERROR))
{
// Oops, we didn't get a proper answer we can use for the next loop.
// Print a warning and simply try one day later.
if (loglevel>0)
logger << "Warning: Demand '" << l << "': Lazy retry" << endl;
plan_date = copy_plan_date + data->getSolver()->getLazyDelay();
}
else
// Use the next-date answer from the solver
plan_date = next_date;
}
else
{
// Accepting this answer
if (data->state->a_qty + ROUNDING_ERROR < q_qty)
{
// The demand was only partially planned. We need to do a new
// 'coordinated' planning run.
// Delete operationplans created in the 'testing round'
data->rollback(topcommand);
// Create the correct operationplans
if (loglevel>=2)
logger << "Demand '" << l << "' plans coordination." << endl;
data->getSolver()->setLogLevel(0);
double tmpresult = 0;
try
{
for(double remainder = data->state->a_qty;
remainder > ROUNDING_ERROR; remainder -= data->state->a_qty)
{
data->state->q_qty = remainder;
data->state->q_date = copy_plan_date;
data->state->curDemand = const_cast<Demand*>(l);
data->state->curBuffer = NULL;
deliveryoper->solve(*this,v);
if (data->state->a_qty < ROUNDING_ERROR)
{
logger << "Warning: Demand '" << l << "': Failing coordination" << endl;
break;
}
tmpresult += data->state->a_qty;
}
}
catch (...)
{
data->getSolver()->setLogLevel(loglevel);
throw;
}
data->getSolver()->setLogLevel(loglevel);
data->state->a_qty = tmpresult;
if (tmpresult == 0) break;
}
// Register the new operationplans. We need to make sure that the
// correct execute method is called!
if (data->getSolver()->getAutocommit())
{
data->getSolver()->scanExcess(data);
data->CommandManager::commit();
}
// Update the quantity to plan in the next loop
plan_qty -= data->state->a_qty;
best_a_qty = 0.0; // Reset 'best-answer' remember
}
}
// Repeat while there is still a quantity left to plan and we aren't
// exceeding the maximum delivery delay.
while (plan_qty > ROUNDING_ERROR
&& ((data->getSolver()->getPlanType() != 2 && plan_date < l->getDue() + l->getMaxLateness())
|| (data->getSolver()->getPlanType() == 2 && !data->constrainedPlanning && plan_date < l->getDue() + l->getMaxLateness())
|| (data->getSolver()->getPlanType() == 2 && data->constrainedPlanning && plan_date == l->getDue())
));
// Accept the best possible answer.
// We may have skipped it in the previous loop, awaiting a still better answer
if (best_a_qty > 0.0 && data->constrainedPlanning)
{
if (loglevel>=2) logger << "Demand '" << l << "' accepts a best answer." << endl;
data->getSolver()->setLogLevel(0);
try
{
for (double remainder = best_q_qty;
remainder > ROUNDING_ERROR && remainder > l->getMinShipment();
remainder -= data->state->a_qty)
{
data->state->q_qty = remainder;
data->state->q_date = best_q_date;
data->state->curDemand = const_cast<Demand*>(l);
data->state->curBuffer = NULL;
deliveryoper->solve(*this,v);
if (data->state->a_qty < ROUNDING_ERROR)
{
logger << "Warning: Demand '" << l << "': Failing accepting best answer" << endl;
break;
}
}
if (data->getSolver()->getAutocommit())
{
data->getSolver()->scanExcess(data);
data->CommandManager::commit();
}
}
catch (...)
{
data->getSolver()->setLogLevel(loglevel);
throw;
}
data->getSolver()->setLogLevel(loglevel);
}
// Reset the state stack to the position we found it at.
while (data->state > mystate) data->pop();
}
catch (...)
{
// Clean up if any exception happened during the planning of the demand
while (data->state > mystate) data->pop();
data->rollback(topcommand);
throw;
}
}
DECLARE_EXPORT void SolverMRP::chooseResource(const Load* l, void* v) // @todo handle unconstrained plan!!!!
{
if (!l->getSkill() && !l->getResource()->isGroup())
{
// CASE 1: No skill involved, and no aggregate resource either
l->getResource()->solve(*this, v);
return;
}
// CASE 2: Skill involved, or aggregate resource
SolverMRPdata* data = static_cast<SolverMRPdata*>(v);
unsigned int loglevel = data->getSolver()->getLogLevel();
// Control the planning mode
bool originalPlanningMode = data->constrainedPlanning;
data->constrainedPlanning = true;
// Don't keep track of the constraints right now
bool originalLogConstraints = data->logConstraints;
data->logConstraints = false;
// Initialize
Date min_next_date(Date::infiniteFuture);
LoadPlan *lplan = data->state->q_loadplan;
Resource *bestAlternateSelection = NULL;
double bestCost = DBL_MAX;
bool qualified_resource_exists = false;
double bestAlternateValue = DBL_MAX;
double bestAlternateQuantity = DBL_MIN;
double beforeCost = data->state->a_cost;
double beforePenalty = data->state->a_penalty;
OperationPlanState originalOpplan(lplan->getOperationPlan());
double originalLoadplanQuantity = lplan->getQuantity();
data->getSolver()->setLogLevel(0); // Silence during this loop
// Loop over all candidate resources
stack<Resource*> res_stack;
res_stack.push(l->getResource());
while (!res_stack.empty())
{
// Pick next resource
Resource* res = res_stack.top();
res_stack.pop();
// If it's an aggregate, push it's members on the stack
if (res->isGroup())
{
for (Resource::memberIterator x = res->beginMember(); x != Resource::end(); ++x)
res_stack.push(&*x);
continue;
}
// Check if the resource has the right skill
if (l->getSkill())
{
bool isqualified = false;
for (Resource::skilllist::const_iterator i = res->getSkills().begin();
i != res->getSkills().end() && !isqualified; ++i)
{
if (i->getSkill() == l->getSkill()
&& originalOpplan.start >= i->getEffective().getStart()
&& originalOpplan.end <= i->getEffective().getEnd())
isqualified = true;
}
// Next resource in the loop if not qualified
if (!isqualified) continue; // TODO if there is a date effective skill, we need to consider it in the reply
}
qualified_resource_exists = true;
// Switch to this resource
data->state->q_loadplan = lplan; // because q_loadplan can change!
lplan->setResource(res);
lplan->getOperationPlan()->restore(originalOpplan);
data->state->q_qty = lplan->getQuantity();
data->state->q_date = lplan->getDate();
// Plan the resource
CommandManager::Bookmark* topcommand = data->setBookmark();
try { res->solve(*this,data); }
catch (...)
{
data->getSolver()->setLogLevel(loglevel);
data->constrainedPlanning = originalPlanningMode;
data->logConstraints = originalLogConstraints;
data->rollback(topcommand);
throw;
}
data->rollback(topcommand);
// Evaluate the result
if (data->state->a_qty > ROUNDING_ERROR
&& lplan->getOperationPlan()->getQuantity() > 0)
{
double deltaCost = data->state->a_cost - beforeCost;
double deltaPenalty = data->state->a_penalty - beforePenalty;
// Message
if (loglevel>1)
logger << indent(l->getOperation()->getLevel()) << " Operation '"
<< l->getOperation()->getName() << "' evaluates alternate '"
<< res << "': cost " << deltaCost
<< ", penalty " << deltaPenalty << endl;
data->state->a_cost = beforeCost;
data->state->a_penalty = beforePenalty;
double val = 0.0;
switch (l->getSearch())
{
case PRIORITY:
val = 1; // @todo skill-resource model doesn't have a priority field yet
break;
case MINCOST:
val = deltaCost / lplan->getOperationPlan()->getQuantity();
break;
case MINPENALTY:
val = deltaPenalty / lplan->getOperationPlan()->getQuantity();
break;
case MINCOSTPENALTY:
val = (deltaCost + deltaPenalty) / lplan->getOperationPlan()->getQuantity();
break;
default:
LogicException("Unsupported search mode for alternate load");
}
if (val + ROUNDING_ERROR < bestAlternateValue
|| (fabs(val - bestAlternateValue) < ROUNDING_ERROR
&& lplan->getOperationPlan()->getQuantity() > bestAlternateQuantity))
{
// Found a better alternate
bestAlternateValue = val;
bestAlternateSelection = res;
bestAlternateQuantity = lplan->getOperationPlan()->getQuantity();
}
}
else if (loglevel>1)
logger << indent(l->getOperation()->getLevel()) << " Operation '"
<< l->getOperation()->getName() << "' evaluates alternate '"
<< lplan->getResource() << "': not available before "
<< data->state->a_date << endl;
// Keep track of best next date
if (data->state->a_date < min_next_date)
min_next_date = data->state->a_date;
}
data->getSolver()->setLogLevel(loglevel);
// Not a single resource has the appropriate skills. You're joking?
if (!qualified_resource_exists)
throw DataException("No qualified resource exists for load");
// Restore the best candidate we found in the loop above
if (bestAlternateSelection)
{
// Message
if (loglevel>1)
logger << indent(l->getOperation()->getLevel()) << " Operation '"
<< l->getOperation()->getName() << "' chooses alternate '"
<< bestAlternateSelection << "' " << l->getSearch() << endl;
// Switch back
data->state->q_loadplan = lplan; // because q_loadplan can change!
data->state->a_cost = beforeCost;
data->state->a_penalty = beforePenalty;
if (lplan->getResource() != bestAlternateSelection)
lplan->setResource(bestAlternateSelection);
lplan->getOperationPlan()->restore(originalOpplan);
data->state->q_qty = lplan->getQuantity();
data->state->q_date = lplan->getDate();
bestAlternateSelection->solve(*this,data);
// Restore the planning mode
data->constrainedPlanning = originalPlanningMode;
data->logConstraints = originalLogConstraints;
return;
}
// 7) No alternate gave a good result
data->state->a_date = min_next_date;
data->state->a_qty = 0;
// Restore the planning mode
data->constrainedPlanning = originalPlanningMode;
// Maintain the constraint list
if (originalLogConstraints)
{
data->planningDemand->getConstraints().push(
ProblemCapacityOverload::metadata,
l->getResource(), originalOpplan.start, originalOpplan.end,
-originalLoadplanQuantity);
}
data->logConstraints = originalLogConstraints;
if (loglevel>1)
logger << indent(lplan->getOperationPlan()->getOperation()->getLevel()) <<
" Alternate load doesn't find supply on any alternate : "
<< data->state->a_qty << " " << data->state->a_date << endl;
}
void SolverMRP::solve(const Load* l, void* v)
{
// Note: This method is only called for decrease loadplans and for the leading
// load of an alternate group. See SolverMRP::checkOperation
SolverMRPdata* data = static_cast<SolverMRPdata*>(v);
unsigned int loglevel = data->getSolver()->getLogLevel();
if (data->state->q_qty >= 0.0)
{
// The loadplan is an increase in size, and the resource solver only needs
// the decreases.
data->state->a_qty = data->state->q_qty;
data->state->a_date = data->state->q_date;
return;
}
if (!l->hasAlternates() && !l->getAlternate())
{
// CASE I: It is not an alternate load.
// Delegate the answer immediately to the resource
chooseResource(l, data);
return;
}
// CASE II: It is an alternate load.
// We ask each alternate load in order of priority till we find a load
// that has a non-zero reply.
// 1) collect a list of alternates
list<const Load*> thealternates;
const Load *x = l->hasAlternates() ? l : l->getAlternate();
SearchMode search = l->getSearch();
for (Operation::loadlist::const_iterator i = l->getOperation()->getLoads().begin();
i != l->getOperation()->getLoads().end(); ++i)
if ((i->getAlternate() == x || &*i == x)
&& i->getEffective().within(data->state->q_loadplan->getDate()))
thealternates.push_back(&*i);
// 2) Sort the list
thealternates.sort(sortLoad); // @todo cpu-intensive - better is to maintain the list in the correct order
// 3) Control the planning mode
bool originalPlanningMode = data->constrainedPlanning;
data->constrainedPlanning = true;
// Don't keep track of the constraints right now
bool originalLogConstraints = data->logConstraints;
data->logConstraints = false;
// 4) Loop through all alternates or till we find a non-zero
// reply (priority search)
Date min_next_date(Date::infiniteFuture);
LoadPlan *lplan = data->state->q_loadplan;
double bestAlternateValue = DBL_MAX;
double bestAlternateQuantity = DBL_MIN;
const Load* bestAlternateSelection = NULL;
double beforeCost = data->state->a_cost;
double beforePenalty = data->state->a_penalty;
OperationPlanState originalOpplan(lplan->getOperationPlan());
double originalLoadplanQuantity = data->state->q_loadplan->getQuantity();
for (list<const Load*>::const_iterator i = thealternates.begin();
i != thealternates.end();)
{
const Load *curload = *i;
data->state->q_loadplan = lplan; // because q_loadplan can change!
// 4a) Switch to this load
if (lplan->getLoad() != curload) lplan->setLoad(curload);
lplan->getOperationPlan()->restore(originalOpplan);
data->state->q_qty = lplan->getQuantity();
data->state->q_date = lplan->getDate();
// 4b) Ask the resource
// TODO XXX Need to insert another loop here! It goes over all resources qualified for the required skill.
// The qualified resources need to be sorted based on their cost. If the cost is the same we should use a decent tie breaker, eg number of skills or number of loads.
// The first resource with the qualified skill that is available will be used.
CommandManager::Bookmark* topcommand = data->setBookmark();
if (search == PRIORITY)
curload->getResource()->solve(*this,data);
else
{
data->getSolver()->setLogLevel(0);
try {curload->getResource()->solve(*this,data);}
catch (...)
{
data->getSolver()->setLogLevel(loglevel);
// Restore the planning mode
data->constrainedPlanning = originalPlanningMode;
data->logConstraints = originalLogConstraints;
throw;
}
data->getSolver()->setLogLevel(loglevel);
}
// 4c) Evaluate the result
if (data->state->a_qty > ROUNDING_ERROR
&& lplan->getOperationPlan()->getQuantity() > 0)
{
if (search == PRIORITY)
{
// Priority search: accept any non-zero reply
// Restore the planning mode
data->constrainedPlanning = originalPlanningMode;
data->logConstraints = originalLogConstraints;
return;
}
else
{
// Other search modes: evaluate all
double deltaCost = data->state->a_cost - beforeCost;
double deltaPenalty = data->state->a_penalty - beforePenalty;
// Message
if (loglevel>1 && search != PRIORITY)
logger << indent(l->getOperation()->getLevel()) << " Operation '"
<< l->getOperation()->getName() << "' evaluates alternate '"
<< curload->getResource() << "': cost " << deltaCost
<< ", penalty " << deltaPenalty << endl;
if (deltaCost < ROUNDING_ERROR && deltaPenalty < ROUNDING_ERROR)
{
// Zero cost and zero penalty on this alternate. It won't get any better
// than this, so we accept this alternate.
if (loglevel>1)
logger << indent(l->getOperation()->getLevel()) << " Operation '"
<< l->getOperation()->getName() << "' chooses alternate '"
<< curload->getResource() << "' " << search << endl;
// Restore the planning mode
data->constrainedPlanning = originalPlanningMode;
data->logConstraints = originalLogConstraints;
return;
}
data->state->a_cost = beforeCost;
data->state->a_penalty = beforePenalty;
double val = 0.0;
switch (search)
{
case MINCOST:
val = deltaCost / lplan->getOperationPlan()->getQuantity();
break;
case MINPENALTY:
val = deltaPenalty / lplan->getOperationPlan()->getQuantity();
break;
case MINCOSTPENALTY:
val = (deltaCost + deltaPenalty) / lplan->getOperationPlan()->getQuantity();
break;
default:
LogicException("Unsupported search mode for alternate load");
}
if (val + ROUNDING_ERROR < bestAlternateValue
|| (fabs(val - bestAlternateValue) < ROUNDING_ERROR
&& lplan->getOperationPlan()->getQuantity() > bestAlternateQuantity))
{
// Found a better alternate
bestAlternateValue = val;
bestAlternateSelection = curload;
bestAlternateQuantity = lplan->getOperationPlan()->getQuantity();
}
}
}
else if (loglevel>1 && search != PRIORITY)
logger << indent(l->getOperation()->getLevel()) << " Operation '"
<< l->getOperation()->getName() << "' evaluates alternate '"
<< curload->getResource() << "': not available before "
<< data->state->a_date << endl;
// 4d) Undo the plan on the alternate
data->rollback(topcommand);
// 4e) Prepare for the next alternate
if (data->state->a_date < min_next_date)
min_next_date = data->state->a_date;
if (++i != thealternates.end() && loglevel>1 && search == PRIORITY)
logger << indent(curload->getOperation()->getLevel()) << " Alternate load switches from '"
<< curload->getResource()->getName() << "' to '"
<< (*i)->getResource()->getName() << "'" << endl;
}
// 5) Unconstrained plan: plan on the first alternate
if (!originalPlanningMode && !(search != PRIORITY && bestAlternateSelection))
{
// Switch to unconstrained planning
data->constrainedPlanning = false;
bestAlternateSelection = *(thealternates.begin());
}
// 6) Finally replan on the best alternate
if (!originalPlanningMode || (search != PRIORITY && bestAlternateSelection))
{
// Message
if (loglevel>1)
logger << indent(l->getOperation()->getLevel()) << " Operation '"
<< l->getOperation()->getName() << "' chooses alternate '"
<< bestAlternateSelection->getResource() << "' " << search << endl;
// Switch back
data->state->q_loadplan = lplan; // because q_loadplan can change!
data->state->a_cost = beforeCost;
data->state->a_penalty = beforePenalty;
if (lplan->getLoad() != bestAlternateSelection)
lplan->setLoad(bestAlternateSelection);
lplan->getOperationPlan()->restore(originalOpplan);
// TODO XXX need to restore also the selected resource with the right skill!
data->state->q_qty = lplan->getQuantity();
data->state->q_date = lplan->getDate();
bestAlternateSelection->getResource()->solve(*this,data);
// Restore the planning mode
data->constrainedPlanning = originalPlanningMode;
data->logConstraints = originalLogConstraints;
return;
}
// 7) No alternate gave a good result
data->state->a_date = min_next_date;
data->state->a_qty = 0;
// Restore the planning mode
data->constrainedPlanning = originalPlanningMode;
// Maintain the constraint list
if (originalLogConstraints)
{
const Load *primary = *(thealternates.begin());
data->planningDemand->getConstraints().push(
ProblemCapacityOverload::metadata,
primary->getResource(), originalOpplan.start, originalOpplan.end,
-originalLoadplanQuantity);
}
data->logConstraints = originalLogConstraints;
if (loglevel>1)
logger << indent(lplan->getOperationPlan()->getOperation()->getLevel()) <<
" Alternate load doesn't find supply on any alternate : "
<< data->state->a_qty << " " << data->state->a_date << endl;
}
void SolverMRP::solveSafetyStock(const Buffer* b, void* v)
{
SolverMRPdata* data = static_cast<SolverMRPdata*>(v);
// Message
if (data->getSolver()->getLogLevel()>1)
logger << indent(b->getLevel()) << " Buffer '" << b->getName()
<< "' replenishes for safety stock" << endl;
// Scan the complete horizon
Date currentDate;
const TimeLine<FlowPlan>::Event *prev = nullptr;
double shortage(0.0);
double current_minimum(0.0);
Buffer::flowplanlist::const_iterator cur=b->getFlowPlans().begin();
while (true)
{
// Iterator has now changed to a new date or we have arrived at the end.
// If multiple flows are at the same moment in time, we are not interested
// in the inventory changes. It gets interesting only when a certain
// inventory level remains unchanged for a certain time.
if ((cur == b->getFlowPlans().end() || cur->getDate()>currentDate) && prev)
{
// Some variables
double theOnHand = prev->getOnhand();
double theDelta = theOnHand - current_minimum + shortage;
bool loop = true;
// Evaluate the situation at the last flowplan before the date change.
// Is there a shortage at that date?
Date nextAskDate;
while (theDelta < -ROUNDING_ERROR && b->getProducingOperation() && loop)
{
// Create supply
data->state->curBuffer = const_cast<Buffer*>(b);
data->state->q_qty = -theDelta;
data->state->q_date = nextAskDate ? nextAskDate : prev->getDate();
// Make sure the new operationplans don't inherit an owner.
// When an operation calls the solve method of suboperations, this field is
// used to pass the information about the owner operationplan down. When
// solving for buffers we must make sure NOT to pass owner information.
// At the end of solving for a buffer we need to restore the original
// settings...
data->state->curOwnerOpplan = nullptr;
// Note that the supply created with the next line changes the
// onhand value at all later dates!
CommandManager::Bookmark* topcommand = data->setBookmark();
b->getProducingOperation()->solve(*this,v);
if (data->state->a_qty > ROUNDING_ERROR)
// If we got some extra supply, we retry to get some more supply.
// Only when no extra material is obtained, we give up.
theDelta += data->state->a_qty;
else
{
data->rollback(topcommand);
if ( (cur != b->getFlowPlans().end() && data->state->a_date < cur->getDate())
|| (cur == b->getFlowPlans().end() && data->state->a_date < Date::infiniteFuture) )
nextAskDate = data->state->a_date;
else
loop = false;
}
}
}
// We have reached the end of the flowplans. Breaking out of the loop
// needs to be done here because in the next statements we are accessing
// *cur, which isn't valid at the end of the list
if (cur == b->getFlowPlans().end()) break;
// The minimum or the maximum have changed
// Note that these limits can be updated only after the processing of the
// date change in the statement above. Otherwise the code above would
// already use the new value before the intended date.
if (cur->getEventType() == 3) current_minimum = cur->getMin();
// Update the pointer to the previous flowplan.
prev = &*cur;
currentDate = cur->getDate();
++cur;
}
// Message
if (data->getSolver()->getLogLevel()>1)
logger << indent(b->getLevel()) << " Buffer '" << b->getName()
<< "' solved for safety stock" << endl;
}
/** @todo The flow quantity is handled at the wrong place. It needs to be
* handled by the operation, since flows can exist on multiple suboperations
* with different quantities. The buffer solve can't handle this, because
* it only calls the solve() for the producing operation...
* Are there some situations where the operation solver doesn't know enough
* on the buffer behavior???
*/
void SolverMRP::solve(const Buffer* b, void* v)
{
// Call the user exit
SolverMRPdata* data = static_cast<SolverMRPdata*>(v);
if (userexit_buffer) userexit_buffer.call(b, PythonData(data->constrainedPlanning));
// Verify the iteration limit isn't exceeded.
if (data->getSolver()->getIterationMax()
&& ++data->iteration_count > data->getSolver()->getIterationMax())
{
ostringstream ch;
ch << "Maximum iteration count " << data->getSolver()->getIterationMax() << " exceeded";
throw RuntimeException(ch.str());
}
// Safety stock planning is refactored to a separate method
double requested_qty(data->state->q_qty);
if (requested_qty == -1.0)
{
solveSafetyStock(b,v);
return;
}
Date requested_date(data->state->q_date);
bool tried_requested_date(false);
// Message
if (data->getSolver()->getLogLevel()>1)
logger << indent(b->getLevel()) << " Buffer '" << b->getName()
<< "' is asked: " << data->state->q_qty << " " << data->state->q_date << endl;
// Store the last command in the list, in order to undo the following
// commands if required.
CommandManager::Bookmark* topcommand = data->setBookmark();
OperationPlan *prev_owner_opplan = data->state->curOwnerOpplan;
// Evaluate the buffer profile and solve shortages by asking more material.
// The loop goes from the requested date till the very end. Whenever the
// event date changes, we evaluate if a shortage exists.
Date currentDate;
const TimeLine<FlowPlan>::Event *prev = nullptr;
double shortage(0.0);
Date extraSupplyDate(Date::infiniteFuture);
Date extraInventoryDate(Date::infiniteFuture);
double cumproduced = (b->getFlowPlans().rbegin() == b->getFlowPlans().end())
? 0
: b->getFlowPlans().rbegin()->getCumulativeProduced();
double current_minimum(0.0);
double unconfirmed_supply(0.0);
for (Buffer::flowplanlist::const_iterator cur=b->getFlowPlans().begin();
; ++cur)
{
if(&*cur && cur->getEventType() == 1)
{
const FlowPlan* fplan = static_cast<const FlowPlan*>(&*cur);
if (!fplan->getOperationPlan()->getRawIdentifier()
&& fplan->getQuantity()>0
&& fplan->getOperationPlan()->getOperation() != b->getProducingOperation())
unconfirmed_supply += fplan->getQuantity();
}
// Iterator has now changed to a new date or we have arrived at the end.
// If multiple flows are at the same moment in time, we are not interested
// in the inventory changes. It gets interesting only when a certain
// inventory level remains unchanged for a certain time.
if ((cur == b->getFlowPlans().end() || cur->getDate()>currentDate) && prev)
{
// Some variables
Date theDate = prev->getDate();
double theOnHand = prev->getOnhand();
double theDelta = theOnHand - current_minimum + shortage;
// Evaluate the situation at the last flowplan before the date change.
// Is there a shortage at that date?
// We have 3 ways to resolve it:
// - Scan backward for a producer we can combine with to make a
// single batch.
// - Scan forward for producer we can replace in a single batch.
// - Create new supply for the shortage at that date.
// Solution one: we scan backward in time for producers we can merge with.
if (theDelta < -ROUNDING_ERROR
&& b->getMinimumInterval() >= 0L
&& prev
&& prev->getDate() >= theDate - b->getMinimumInterval())
{
Operation *prevOper = nullptr;
DateRange prevDates;
double prevQty = 0.0;
Buffer::flowplanlist::const_iterator prevbatchiter = b->getFlowPlans().end();
for (Buffer::flowplanlist::const_iterator batchiter = prev;
batchiter != b->getFlowPlans().end() && batchiter->getDate() >= theDate - b->getMinimumInterval();
prevbatchiter = batchiter--)
{
// Check if it is an unlocked producing operationplan
if (batchiter->getQuantity() <= 0) continue;
const FlowPlan* batchcandidate = nullptr;
if (batchiter->getEventType() == 1)
batchcandidate = static_cast<const FlowPlan*>(&*batchiter);
if (!batchcandidate || batchcandidate->getOperationPlan()->getLocked())
continue;
// Store date and quantity of the candidate
Date batchdate = batchcandidate->getDate();
double batchqty = batchcandidate->getOperationPlan()->getTotalFlow(b) - theDelta;
double consumed_in_window = b->getFlowPlans().getFlow(batchcandidate, b->getMinimumInterval(), true);
if (batchqty > consumed_in_window)
batchqty = consumed_in_window;
Operation* candidate_operation = batchcandidate->getOperationPlan()->getOperation();
DateRange candidate_dates = batchcandidate->getOperationPlan()->getDates();
double candidate_qty = batchcandidate->getOperationPlan()->getQuantity();
// Verify we haven't tried the same kind of candidate before
if (candidate_operation == prevOper
&& candidate_dates == prevDates
&& fabs(candidate_qty - prevQty) < ROUNDING_ERROR)
continue;
prevOper = candidate_operation;
prevDates = candidate_dates;
prevQty = candidate_qty;
// Delete existing producer, and propagate the deletion upstream
CommandManager::Bookmark* batchbookmark = data->setBookmark();
data->operator_delete->solve(batchcandidate->getOperationPlan());
// Create new producer
short loglevel = data->getSolver()->getLogLevel();
try
{
data->getSolver()->setLogLevel(0);
data->state->curBuffer = const_cast<Buffer*>(b);
data->state->q_qty = batchqty;
// We need to add the post-operation time, because the operation
// solver will subtract it again. For merging operationaplans we
// want to plan *exactly* at the date of the existing operationplan.
data->state->q_date =
batchdate + b->getProducingOperation()->getPostTime();
data->state->curOwnerOpplan = nullptr;
b->getProducingOperation()->solve(*this, v);
}
catch (...)
{
data->getSolver()->setLogLevel(loglevel);
throw;
}
data->getSolver()->setLogLevel(loglevel);
// Check results
if (data->state->a_qty < batchqty - ROUNDING_ERROR)
{
// It didn't work.
if (loglevel > 1)
logger << indent(b->getLevel())
<< " Rejected resized batch '" << candidate_operation
<< "' " << candidate_dates << " " << candidate_qty << endl;
data->rollback(batchbookmark);
// Assure batchiter remains valid
batchiter = prevbatchiter;
if (batchiter != b->getFlowPlans().end())
--batchiter;
}
else
{
// It worked.
if (loglevel > 1)
logger << indent(b->getLevel())
<< " Accepting resized batch '" << candidate_operation
<< "' " << candidate_dates << " " << candidate_qty << endl;
theDelta = 0.0;
break;
}
// Assure the prev pointer remains valid after this loop
Buffer::flowplanlist::const_iterator c = cur;
--c;
if (c == b->getFlowPlans().end())
{
c = b->getFlowPlans().rbegin();
if (c == b->getFlowPlans().end())
prev = nullptr;
else
prev = &*c;
}
else
prev = &*c;
}
}
// Solution two: we scan forward in time for producers we can replace.
if (theDelta < -ROUNDING_ERROR
&& b->getMinimumInterval() >= 0L
&& cur != b->getFlowPlans().end()
&& cur->getDate() <= theDate + b->getMinimumInterval())
{
Operation *prevOper = nullptr;
DateRange prevDates;
double prevQty = 0.0;
Buffer::flowplanlist::const_iterator prevbatchiter = b->getFlowPlans().end();
for (Buffer::flowplanlist::const_iterator batchiter = cur;
batchiter != b->getFlowPlans().end() && batchiter->getDate() <= theDate + b->getMinimumInterval();
prevbatchiter = batchiter++)
{
// Check if it is an unlocked producing operationplan
if (batchiter->getQuantity() <= 0) continue;
const FlowPlan* batchcandidate = nullptr;
if (batchiter->getEventType() == 1)
batchcandidate = static_cast<const FlowPlan*>(&*batchiter);
if (!batchcandidate || batchcandidate->getOperationPlan()->getLocked())
continue;
// Store date and quantity of the candidate
double batchqty = batchcandidate->getQuantity()- theDelta;
double consumed_in_window = b->getFlowPlans().getFlow(prev, b->getMinimumInterval(), true);
if (batchqty > consumed_in_window)
batchqty = consumed_in_window;
Operation* candidate_operation = batchcandidate->getOperationPlan()->getOperation();
DateRange candidate_dates = batchcandidate->getOperationPlan()->getDates();
double candidate_qty = batchcandidate->getOperationPlan()->getQuantity();
// Verify we haven't tried the same kind of candidate before
if (candidate_operation == prevOper
&& prevDates == candidate_dates
&& fabs(candidate_qty - prevQty) < ROUNDING_ERROR)
continue;
prevOper = candidate_operation;
prevDates = candidate_dates;
prevQty = candidate_qty;
// Delete existing producer, and propagate the deletion upstream
CommandManager::Bookmark* batchbookmark = data->setBookmark();
data->operator_delete->solve(batchcandidate->getOperationPlan());
// Create new producer
short loglevel = data->getSolver()->getLogLevel();
try
{
data->getSolver()->setLogLevel(0);
data->state->curBuffer = const_cast<Buffer*>(b);
data->state->q_qty = batchqty;
data->state->q_date = theDate;
data->state->curOwnerOpplan = nullptr;
b->getProducingOperation()->solve(*this, v);
}
catch (...)
{
data->getSolver()->setLogLevel(loglevel);
throw;
}
data->getSolver()->setLogLevel(loglevel);
// Check results
if (data->state->a_qty < batchqty - ROUNDING_ERROR)
{
// It didn't work.
if (loglevel > 1)
logger << indent(b->getLevel())
<< " Rejected joining batch with '" << candidate_operation
<< "' " << candidate_dates << " " << candidate_qty << endl;
data->rollback(batchbookmark);
// Assure batchiter remains valid
batchiter = prevbatchiter;
if (batchiter != b->getFlowPlans().end())
++batchiter;
}
else
{
// It worked.
if (loglevel > 1)
logger << indent(b->getLevel())
<< " Accepted joining batch with '" << candidate_operation
<< "' " << candidate_dates << " " << candidate_qty << endl;
theDelta = 0.0;
// Assure the cur iterator remains valid after this loop
cur = prev;
if (cur != b->getFlowPlans().end())
++cur;
break;
}
// Assure the cur iterator remains valid after this loop
cur = prev;
if (cur != b->getFlowPlans().end())
++cur;
}
}
// Solution three: create supply at the shortage date itself
if (theDelta < -ROUNDING_ERROR)
{
// Can we get extra supply to solve the problem, or part of it?
// If the shortage already starts before the requested date, it
// was not created by the newly added flowplan, but existed before.
// We don't consider this as a shortage for the current flowplan,
// and we want our flowplan to try to repair the previous problems
// if it can...
bool loop = true;
while (b->getProducingOperation() && theDate >= requested_date && loop)
{
// Create supply
data->state->curBuffer = const_cast<Buffer*>(b);
data->state->q_qty = -theDelta;
data->state->q_date = theDate;
// Check whether this date doesn't match with the requested date.
// See a bit further why this is required.
if (data->state->q_date == requested_date) tried_requested_date = true;
// Make sure the new operationplans don't inherit an owner.
// When an operation calls the solve method of suboperations, this field is
// used to pass the information about the owner operationplan down. When
// solving for buffers we must make sure NOT to pass owner information.
// At the end of solving for a buffer we need to restore the original
// settings...
data->state->curOwnerOpplan = nullptr;
// Note that the supply created with the next line changes the
// onhand value at all later dates!
b->getProducingOperation()->solve(*this,v);
// Evaluate the reply date. The variable extraSupplyDate will store
// the date when the producing operation tells us it can get extra
// supply.
if (data->state->a_date < extraSupplyDate
&& data->state->a_date > requested_date)
extraSupplyDate = data->state->a_date;
// If we got some extra supply, we retry to get some more supply.
// Only when no extra material is obtained, we give up.
// When solving for safety stock or when the parameter allowsplit is
// set to false we need to get a single replenishing operationplan.
if (data->state->a_qty > ROUNDING_ERROR
&& data->state->a_qty < -theDelta - ROUNDING_ERROR
&& ((data->getSolver()->getAllowSplits() && !data->safety_stock_planning)
|| data->state->a_qty == b->getProducingOperation()->getSizeMaximum())
)
theDelta += data->state->a_qty;
else
loop = false;
}
// Not enough supply was received to repair the complete problem
if (prev && prev->getOnhand() + shortage < -ROUNDING_ERROR)
{
// Keep track of the shorted quantity.
// Only consider shortages later than the requested date.
if (theDate >= requested_date)
shortage = -prev->getOnhand();
// Reset the date from which excess material is in the buffer. This
// excess material can be used to compute the date when the buffer
// can be asked again for additional supply.
extraInventoryDate = Date::infiniteFuture;
}
}
else if (theDelta > unconfirmed_supply + ROUNDING_ERROR)
// There is excess material at this date (coming from planned/frozen
// material arrivals, surplus material created by lotsized operations,
// etc...)
// The unconfirmed_supply element is required to exclude any of the
// excess inventory we may have caused ourselves. Such situations are
// possible when there are loops in the supply chain.
if (theDate > requested_date
&& extraInventoryDate == Date::infiniteFuture)
extraInventoryDate = theDate;
}
// We have reached the end of the flowplans. Breaking out of the loop
// needs to be done here because in the next statements we are accessing
// *cur, which isn't valid at the end of the list
if (cur == b->getFlowPlans().end()) break;
// The minimum has changed.
// Note that these limits can be updated only after the processing of the
// date change in the statement above. Otherwise the code above would
// already use the new value before the intended date.
// If the flag getPlanSafetyStockFirst is set, then we need to replenish
// up to the minimum quantity. If it is not set (which is the default) then
// we only replenish up to 0.
if (cur->getEventType() == 3 && (getPlanSafetyStockFirst() || data->safety_stock_planning))
current_minimum = cur->getMin();
// Update the pointer to the previous flowplan.
prev = &*cur;
currentDate = cur->getDate();
}
// Note: the variable extraInventoryDate now stores the date from which
// excess material is available in the buffer. The excess
// We don't need to care how much material is lying there.
// Check for supply at the requested date
// Isn't this included in the normal loop? In some cases it is indeed, but
// sometimes it isn't because in the normal loop there may still have been
// onhand available and the shortage only shows at a later date than the
// requested date.
// E.g. Initial situation: After extra consumer at time y:
// -------+ --+
// | |
// +------ +---+
// |
// 0 -------y------ 0 --y---x-----
// |
// +-----
// The first loop only checks for supply at times x and later. If it is not
// feasible, we now check for supply at time y. It will create some extra
// inventory, but at least the demand is met.
// @todo The buffer solver could move backward in time from x till time y,
// and try multiple dates. This would minimize the excess inventory created.
while (shortage > ROUNDING_ERROR
&& b->getProducingOperation() && !tried_requested_date)
{
// Create supply at the requested date
data->state->curBuffer = const_cast<Buffer*>(b);
data->state->q_qty = shortage;
data->state->q_date = requested_date;
// Make sure the new operationplans don't inherit an owner.
// When an operation calls the solve method of suboperations, this field is
// used to pass the information about the owner operationplan down. When
// solving for buffers we must make sure NOT to pass owner information.
// At the end of solving for a buffer we need to restore the original
// settings...
data->state->curOwnerOpplan = nullptr;
// Note that the supply created with the next line changes the onhand value
// at all later dates!
// Note that asking at the requested date doesn't keep the material on
// stock to a minimum.
if (requested_qty - shortage < ROUNDING_ERROR)
data->rollback(topcommand);
b->getProducingOperation()->solve(*this,v);
// Evaluate the reply
if (data->state->a_date < extraSupplyDate
&& data->state->a_date > requested_date)
extraSupplyDate = data->state->a_date;
if (data->state->a_qty > ROUNDING_ERROR)
shortage -= data->state->a_qty;
else
tried_requested_date = true;
}
// Final evaluation of the replenishment
if (data->constrainedPlanning && data->getSolver()->isConstrained())
{
// Use the constrained planning result
data->state->a_qty = requested_qty - shortage;
if (data->state->a_qty < ROUNDING_ERROR)
{
data->rollback(topcommand);
data->state->a_qty = 0.0;
}
data->state->a_date = (extraInventoryDate < extraSupplyDate) ?
extraInventoryDate :
extraSupplyDate;
// Monitor as a constraint if there is no producing operation.
// Note that if there is a producing operation the constraint is flagged
// on the operation instead of on this buffer.
if (!b->getProducingOperation() && data->logConstraints && shortage > ROUNDING_ERROR && data->planningDemand)
data->planningDemand->getConstraints().push(ProblemMaterialShortage::metadata,
b, requested_date, Date::infiniteFuture, shortage);
}
else
{
// Enough inventory or supply available, or not material constrained.
// In case of a plan that is not material constrained, the buffer tries to
// solve for shortages as good as possible. Only in the end we 'lie' about
// the result to the calling function. Material shortages will then remain
// in the buffer.
data->state->a_qty = requested_qty;
data->state->a_date = Date::infiniteFuture;
}
// Restore the owning operationplan.
data->state->curOwnerOpplan = prev_owner_opplan;
// Reply quantity must be greater than 0
assert( data->state->a_qty >= 0 );
// Increment the cost
// Only the quantity consumed directly from the buffer is counted.
// The cost of the material supply taken from producing operations is
// computed seperately and not considered here.
if (b->getItem() && data->state->a_qty > 0)
{
if (b->getFlowPlans().empty())
cumproduced = 0.0;
else
cumproduced = b->getFlowPlans().rbegin()->getCumulativeProduced() - cumproduced;
if (data->state->a_qty > cumproduced)
data->state->a_cost += (data->state->a_qty - cumproduced) * b->getItem()->getPrice();
}
// Message
if (data->getSolver()->getLogLevel()>1)
logger << indent(b->getLevel()) << " Buffer '" << b->getName()
<< "' answers: " << data->state->a_qty << " " << data->state->a_date << " "
<< data->state->a_cost << " " << data->state->a_penalty << endl;
}