Production planning and scheduling

An Innovative Real Time Production Management System
A white paper

Abstract
Scheduling is indeed a major issue in all manufacturing and project execution facilities world over. It is also
recognized that if scheduling is efficient and automated huge benefits could result as existing resource usage can
be maximized allowing dramatic increase in number of orders processed at the same time substantially reducing
cost of production while ensuring reliability in delivery on the committed date. No wonder scheduling is a hot
research topic and the market is flooded with scheduling systems of sorts. Still a truly efficient and automatic
scheduling system remains an elusive dream.

This white paper lists the six important reasons why a scheduling system fails in real-life situations. It then
describes how a new scheduling system called Talika PMS satisfies all the six critical requirements in detail with real
data supporting the claims from its first major installation.

Visit www.etalika.in for more information and free download

1 Introduction Before we elucidate more on the system features we
would like to re-emphasis importance of scheduling
Day-to-day scheduling of any manufacturing facility in any manufacturing facility and why current
is recognized to be the most important problem to solutions fail to address the problem correctly.
be solved. [1] D. Ouelhadj and S. Petrovic recent
[Oct 2008] study reveals that solutions based on 2 Importance of scheduling
creation of a static schedule are impractical in real-
life situations and discusses several dynamic The only real differentiators to compete in
scheduling approaches only to conclude that more established products and services market are Cost
work is still needed in this field of research. and Reliable delivery. Quality of product / service is
mostly considered a pre-condition to be in business
We wish to present here a complete dynamic real- rather than a differentiator. Both cost and reliable
time micro level scheduling system that is proven to delivery of product / service are directly impacted by
work in the most complex manufacturing facilities. It scheduling.
is a fully scalable, decentralized, multi-location and
user configurable system to suit any manufacturing / 2.1 Scheduling and cost of production
project environment. The core scheduling is fully
automatic and guarantees that all currently allotted It is almost axiomatic to state that a major portion of
tasks in real-time can be executed with a complete cost of production (even exceeding 70% - 80% in
and detailed schedule prediction of all activities for made-to-order industries) is expended in
all orders in-hand. The system automatically coordinating and managing production activities vis-
reschedules in response to real-time events as à-vis the actual cost of value-addition involved.
notified by operators’ handling current tasks on the
shop floor, with an objective to maximize resource Most real life manufacturing involves execution of
utilization while minimizing job cycle time. It offers several individual activities in a complex order to
full micro-level future schedule visibility of all create any saleable final product or service. The
running jobs to predict when each would be over starting point thus is in breaking down an order
given the current load as of NOW. The cycle of requirement into elemental activities that must be
allotting tasks, seeking task-wise feedback on completed in order to accomplish the final product /
allotments made from operators’ on shop floor, and service deliverable: ranging from getting inputs or
re-predicting its impact in subsequent reschedule raw material until final packing and dispatch. Unless
happen every minute 24x7. this detailing is not done, actual value addition
cannot begin. Once it is known “How” the order can
be fulfilled the most difficult job of scheduling

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© 2013, Laxman C Marathe

individual activities of orders begin. It primarily seldom match reality owing to unexpected
translates in deciding what activity must be done, disruptions [3] & [5].
where it should be done (that is using what limited
resources) and when. One can refer to them as the So, any scheduling system that fails to respond to
3W’s. Most expensive and competent personnel in changing situation on ground by failing to reschedule
any manufacturing or project execution facility are and redraw its prediction (Gantt chart) is a misfit in
engaged fully in the process of managing production real life making purported schedule optimality and
that involves, breaking down order execution, efficiency claims hypothetical.
estimating its cost, time and wastages, deciding
what activities to do now and next, taking feedback 3.2 No feedback mechanism
on progress made, follow-up and expediting to meet
deadlines. The whole exercise is repeated all over A scheduling system can only be responsive to what
again by rescheduling to predict and monitor is happening on the shop floor if a feedback
expected completion dates for all orders in hand. mechanism exists. This feedback mechanism should
be both real-time and automatic. Peter Cowling and
Add to this already complex situation, the burden of Marcus Johansson [2] argue in a well researched
estimating when new orders can be delivered given paper that “in many production processes real time
the existing load of orders already in-hand. All this is information may be obtained from process control
now possible to be completely automated resulting computers and other monitoring systems, but most
in a substantial reduction in the cost of production. existing scheduling models are unable to use this
information to effectively influence scheduling
2.2 Scheduling & reliability decisions in real time”. This is a major disconnect
making the schedule infeasible as it is soon out of
Scheduling decisions taken now directly impact synchronization with reality.
expected completion times of all orders in-hand. In
real-life situations one has to deal with several We have recognized that the only authentic real-
orders, each with its own set of individual time source of feedback information from the shop
interdependent activities requiring a certain profile floor is the personnel (Operators’) in charge of
of resources that are both shared and limited. It is performing individual activities. However, each
well impossible, even in small setups, to manually operator can only give feedback on what each one
figure-out impact of real-time decisions on predicted does and that too ideally limited to the current task
completion dates. in-hand. We achieve a seamless feedback
mechanism to the scheduling engine by allocating
Honoring delivery on committed date is more elemental executable tasks in real-time to individual
important than how fast one turns around an order Operators, and seeking task-specific feedback for
in a manufacturing facility. It is only possible to do each such allotted task. The process of task
so, if one is in a position to predict impact of all allotment, progress feedback and subsequent
scheduling decisions taken now on all orders in-hand reschedule to decide what to do next happens 24x7
in real time as an on-going process. automatically.

3 Why conventional scheduling systems fail in the 3.3 Schedule not actionable
real world?
The decision to execute an elemental task or activity
3.1 Static scheduling of an order requires one to take into account several
aspects; availability of inputs, availability of
Scheduling is a widely misunderstood term. Many resources and technical feasibility of performing the
believe plotting activities to be performed on task. Most scheduling systems usually fail on this
different resources on a time scale (Gantt chart) count. Proposed activities are either not actionable
make a schedule. Actually a Gantt chart is just a or represent a group of activities leaving the decision
snap shot of what is likely to happen in the future of what exactly to do now to the operators. In order
given the situation NOW. As one progresses in time to circumvent this problem, many systems offer a
this representation will change because predictions “drag & drop” facility to correct or manipulate
proposed schedule before it is released. As [4] P.

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Velaga asserts, presence of a “drag & drop” facility unaltered any amendment to future task listing in no
indicate an inherent weakness of the scheduling way adds to nervousness. On the contrary, impact
logic. on completion dates of all jobs in hand must be
known immediately not when the next frozen
3.4 Manufacturing facilities are on-going concerns schedule is created.

Getting new orders and completing existing orders is We propose a true scheduling system called Talika
a continual process in real facilities. Existing Production Management System (PMS) that satisfies
commitments cannot generally be disturbed because all the above primary requirements.
of new orders. Situations can become more complex
as orders could be cancelled or amended. Any 4 Overview of Talika PMS
scheduling solution that considers a static order load
is therefore impractical. The system has a distributed architecture as
indicated in Figure-1. At the center is the real-time
3.5 Working in shifts scheduling engine working round-the-clock and is
the live heart of the system. Several different types
Many manufacturing facilities work round the clock of consoles interact with the scheduling engine using
in shifts manned by a different set of personnel. a proprietary protocol that is robust and
Scheduling decisions impact across shifts and the asynchronous making the entire process of
biggest challenge becomes information handover communication absolutely safe.
between shifts. The only remedy is in having the
scheduling systems work 24x7 continuously. There are several different types of consoles each
designed to perform a specific function on the shop
3.6 Stability versus responsiveness floor. Consoles work in a standalone mode but can
also communicate with the scheduling engine, if
Most scheduling systems provide a stable schedule connected, making the entire distributed system live
frozen for a period (usually a few days) and expects and reliable. Exhibit–1 at the end details
it to hold well unless disruptions occur, which functionality of each Console shown in Figure-1 and
inevitably do occur. It is reasoned that having a explains how the automatic scheduling engine drives
continually changing schedule results in shop floor other peripheral or support activities. Most ERP
nervousness. Shop floor nervousness is a myth systems only handle the peripheral activities sans
propagated to hide inability of doing a quick the driving scheduling engine at its heart, making it
reschedule. Operators’ are only concerned with the more of a fancy carcass disconnected from the shop
task in-hand. As long as the current task remains floor.

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Figure-1: Macro system schema

5 How the system works One can also create part CT diagrams for
common work flows in the factory and save
Figure-2 gives an at-a-glance view of how the them as sub-assemblies. Sub-assemblies are
entire system works. building blocks one may use to quickly create a
new complex job definition.
5.1 Starting point
Jobs are stored as proprietary files with a
Job Study Wizard (JSW) is the starting point. As default “*.tlk” extension to any media. One can
already explained each sales person or save, share and reuse stored jobs over and over
concerned agency can have a JSW of their own. again just like a text file.
Potential enquiries can be quickly converted to a
detailed job definition depicted as an easy to 5.2 Scheduling a job
understand component task (CT) diagram. CT
diagram actually represents the micro level It is not necessary all defined jobs be actually
activity work flow for creating one-something of scheduled. Jobs could be defined when we
any value-added service or product. It is more receive an enquiry to estimate its cost and
like a recipe. One can always scale it up or down assess delivery date, but we only need to
to match extent of final output required keeping schedule the order when it matures. When
the CT diagram (recipe) unchanged. It is also scheduled, orders flow over to the scheduling
possible to create, as a one-time exercise, a engine and the process of executing its
bank of most standard CT diagrams (standard constituent tasks begin.
orders) used in the facility. So, defining new
orders may simply translate into picking up an 5.3 Role of scheduling engine and shop floor
appropriate or nearly matching already defined interface: Work Center Console (WCC)
CT diagram and making minor adjustments to it.
Scheduling engine works 24x7 and proactively
controls all factory work centers at a micro level.

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It decides what tasks of which orders can and to the scheduling engine to be taken cognizance
should be actually allotted for execution to the of during the next reschedule that happens
shop floor. Complete information of currently every minute. This cycle of allotting tasks,
allotted tasks flows to the concerned WCC in getting progress and completion notification
real-time. Operators’ acknowledge allotted feedback, and subsequent fresh allotment on
tasks to start execution and notify interim each work center on the shop floor goes on
milestones achieved, until the allotted task is without end.
not over. All notifications flow back in real-time

Figure-2: Working principle at-a-glance

6 Working logic of scheduling engine

Scheduling engine comprises of a set of complex the JSW itself. Only on confirmation, valid
daemons working round-the-clock. Like a orders are communicated to the scheduling
human scheduler does, it always decides what engine. During order definition stage itself a lot
tasks to execute now. The entire optimization of detailing about the job is done including de-
principle could be summed in one line as “if selection of technically non-feasible work
something (read a task) can be done and it centers to execute specific tasks of the job.
should be done then it will be done”. The above User can also specify several guidelines for the
rule automatically guarantees that resource scheduling engine to follow while executing the
utilization is maximized while simultaneously order called “execution preferences”.
reducing job cycle time. Scheduling engine uses its own intelligence
while implementing user specified guidelines
An order is first broken-down to its elemental but ensures they are honored whenever
tasks in form of a CT diagram during definition in possible. Execution preferences are not rigid;

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they can be changed even at run-time after a all tasks in an order. Table-1 below lists the
job is scheduled. Execution preferences could execution preferences and explains what each
be different for each task. However, user can means and how the scheduling engine uses
specify them just once with applicability them while making allotment decisions.
controlled across parts or group of tasks or for

Table-1: Execution Preferences and what they mean
Execution preference What it means Scheduling engine usage
If WIP is not on the critical
Attempt to minimize work-in- chain and has enough time left
progress (WIP) from being to be produced and used then
WIP control
created too much in advance its creation is deferred thereby
and thus remain unused. minimizing WIP build-up on the
shop floor.
Tasks are allotted first by order
priority and then by the future
User desires to change task
Control of task burden on the task within an
execution order, if necessary, at
execution order order. However, user may
run-time.
change this natural order of
execution at run time.
Scheduler tries to honors user
preference with switchover
savings, if any, considered. In
If one has a choice of work
case the first preferred work
Work center choice centers to perform a task then
center is unavailable it tries to
which one to choose?
allot the task on the second
preferred work center and so
on.
Ensuring a particular task is Always tries to execute the said
Locking Option only executed within a user task within the specified period,
specified period. as far as possible.
If the task is on the critical chain
Breaking up a task to run or its execution cannot be
concurrently on more than one deferred any further scheduling
Auto-breaking option
work center with an intention engine will try to optimize and
to reduce task execution time. select the most appropriate
breaking option possible.
Stop and resume task execution
after a holiday, recess period. Scheduler wisely decides to
Spanning Option Commonly referred to as a non- span or not to span depending
scheduling time zone (NSTZ) in on the current situation.
the system.

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It may not be necessary to wait
to start the next value-adding
Scheduler tries to begin the
task that uses or consumes
next value adding task even
what is produced by the current
before the earlier one feeding
task until the current task is not
into the next one is not yet
MCI option over. One can overlap in time
over. Time to initiate the next
both tasks in order to expedite
task can be user decided or left
the order. We can say the
to the scheduling engine to
preceding task gives a mid-
figure out.
course intimation (MCI) to the
next task to begin.
User may want some tasks
(orders) to be executed only
Scheduler ensures the task is
when there is free time
Interleaving option executed whenever there is
available. Contrast this with
nothing urgent to be done.
auto-breaking where the
objective was to expedite.
Especially in long running tasks
interim milestone reached MCF is used constructively to
feedback may be necessary to adjudge the expected
MCF Option
re-adjust expected task completion time for long
completion time. We call it a running tasks.
mid-course feedback (MCF).
NSTZ is an acronym for non-
scheduling time zones. Periods
when the scheduling engine will
not schedule (allot) a fresh task.
Scheduling engine takes
However, an already running
appropriate decision to cut into
task can either by design (or
NSTZ whenever necessary.
NSTZ cut-in option because it is delayed) cut-into
Working during NSTZ is an
an impending NSTZ. System
additional cost and calculated
supports five categories of NSTZ
accordingly.
with varying importance and
user can define how much a
particular task can actually cut
into each of them.

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It is possible for user to specify
that in an order if some task A
is executed on a particular work
center then preferably task B
too should be the next one You can guess concept of
followed by task C and so on. cascading is different from
Valid reason could be controlling task execution
substantial saving in cost and order. The former is applicable
Task line-up
time if done so. We call it task within an order whereas the
cascading. This again could be later could be across orders and
a preferential cascading or a typically is a run-time user
forced cascading when user intervention.
insists that the scheduling
engine waits a pre-determined
period for the next cascaded
task to mature for execution.

In addition to above user specified execution up unless filled-up to some predefined minimum
preferences, the scheduling engine takes into capacity.
consideration several other aspects as well and
does its own run-time adjustments as listed 6.3 Considering time for material movement
below. and normalization

6.1 Work center capacity In real facilities it takes a while for work-in-
progress to be moved from the place it is
Checking if it is possible for a given task to be created to where it is needed for further value-
executed on a work center must be done before addition. This time too must be taken into
each allotment. Our system allows user to account before deciding fresh allotment. Both
define multi-part work centers that could either fixed and variable types of material movement
work as a whole or in parts enabling one to are considered and require separate notification
execute a variety of tasks each requiring it own from a special console called Material
part capacity profile. Movement Console (MMC) given to the person
responsible for material movement.
6.2 Activating work center
Additionally, certain WIP may require time to
Resources and work centers are conventionally set, dry, solidify, etc. We call it time to
thought as synonyms, but in our system a normalize the WIP produced before further
resource has a very special meaning: a work value-addition on it can begin.
center to become active requires resources.
What resources are required to activate a work 6.4 Deciding need for expediting or skipping
center is user defined. Therefore, if a work task allotment
center is currently not active it is necessary to
check for resource availability. Task allotment Breaking a task over more than one work
can only happen if it is possible to activate a centers for concurrent execution is only
work center. This check is done automatically advantageous if the task in question has reached
by the scheduling engine. a critical stage. In our language, has sufficiently
exhausted the available leeway. Scheduler
Activating work centers could also be dependent reckons how much the current leeway available
on capacity usage. A typical case could be an is before taking such decisions. Likewise, if
industrial oven that is uneconomical to be fired- sufficient leeway is available and if the user
desires task allotment may be skipped allowing

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other urgent tasks to be handled in the while raising an alarm for human intervention to
meanwhile. amend order workflow.

Further, if sufficient time is not available to 6.9 Monitor completion is within committed
complete a task as one has an impending NSTZ date
or locked task then the scheduling engine could
either span the task, if possible, or decide to skip Generally one must keep some safety buffer
allotment until later. between when actually an order will be
completed and the date of delivery committed
6.5 Deselecting inappropriate work center to the customer. On each reschedule, expected
completion time for all orders are re-calculated.
At run-time work centers that were originally However, if for some reason order completion
thought appropriate to execute a task may crosses the cut-off date an alarm is raised by the
become inappropriate as they waste more than scheduling engine.
the reported good count of inputs actually
available now. Similarly, in a multi-plant facility 6.10 Monitoring task execution (duration,
if certain WIP is created in one plant and the wastage, cost etc.)
next value-adding work center too is available in
the same plant but not currently free then the Expected duration, cost, wastage, time for the
scheduling engine may decide to wait for it to output from a task to become usable for
become free rather than send WIP to another subsequent value-addition (normalization time)
plant’s work center if doing so is advantageous. and capacity the task may partake of each work
center it can be executed on, are all calculated
6.6 Deciding to hasten-up task execution during job definition stage itself in the JSW.
User can define complex formulae and lookup
No matter how complex a rule one may use to tables using attribute values specific to each
anticipate task’s total duration it is still an task to arrive at these figures. However, the
estimate. When situation demands one may scheduling engine also captures the actual
slightly expedite task execution to finish it faster values in each case. Doing so not only allows
than expected. It is a done thing in practice and one to control deviation task-wise at run-time
the scheduling engine too, if necessary, does the but enables periodic revision of estimation rules
same, of course within user permitted limits. in order to match them to reality as closely as
possible.
6.7 Decision to re-purpose inputs
For example, if any task actual execution time
Identical inputs could be processed by different exceeds its estimated duration it turn black on
tasks to produce something different. the live Gantt chart allowing concerned
Assignment of specific task inputs is rather supervisors to only focus on late tasks. Several
notional and one can, if need be, re-purpose useful reports too can be generated highlighting
inputs to expedite those tasks whose other exceptions. Actual vis-à-vis estimated data can
inputs are deemed available. Human schedulers also be used to tailor a micro-level incentive
often take such decisions and so does the scheme as resource capacity is translated in
scheduling engine provided user allows (or time terms and thus easier to assess and
defines) such a swapping as possible. monitor.

6.8 Decision to freeze part or whole order 6.11 Procurement and maintenance too are
considered tasks
In case of any reported shortfall in WIP count for
any reason it makes sense to temporarily halt We consider procurement of customer inputs
order execution, make good the shortfall and and raw material too as tasks performed by
then resume executing order again. Humans do customer interaction personnel or buyers. Any
take such decisions and so does the scheduling deviation in expected arrivals of inputs has a
engine. It decides to suspend order execution bearing on the overall schedule. Likewise,

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maintenance activities also keep the work 7 Vital statistics from the first successful
centers busy and affect the schedule and thus installation
are treated as tasks.
The entire system is now mature and rigorously
6.12 Actual task execution may not always be tested to exacting conditions in its first full-
successful fledged installation at a medium sized
commercial print setup in India. It has been
Every allotted task may not be completed working for more than 3 years now giving us the
successfully. We have the following options confidence to make it available for the benefit
available with the Operator for an allotted task. of the world at large.
Operator can roll back an allotted task with a
request to reassign it later. In case, Operator The system is user configurable and starts by
has already started working on the task it could defining the manufacturing facility in detail.
still be re-allotted: a way of telling the They include identifying:
scheduling engine that it is not possible to
complete the task now though it can be 7.1 Work centers
completed later by me or by someone else.
Operators’ can pause and resume working on a Listing of individual work centers of the factory,
task. In the worst case, Operators’ can also classified by departments, and if a multi-plant
declare a task as terminated meaning it is no (location) facility, then by plants. The first
more possible to complete the task as inputs are installation is a multi-plant facility. Table-2 gives
either damaged or destroyed - an error details of the work centers and their
condition requiring human intervention to make distribution.
good the shortfall. All the above impact the
schedule and are considered by the scheduling Table-2: First installation work center details
engine. Number of individual work
419
center
Then there are several more activities
performed by the scheduling engine like – Number of departments 47

• Reassessing what is completed until now Number of plants / locations 5
• How much more time existing tasks would
require
7.2 Tasks and what they produce
• The actual time, wastages and costs
(including overtime cost) incurred until now
Tasks get executed on work centers. Tasks
and so on.
produces some things recognized as
“component” and may also require some things
It is very easy to guess, a lot of thinking happens
to add value to, again a “component”. The tasks
to ensure that each allotted task can indeed be
and the components it produces actually make
executed on the shop floor and every
up the CT diagram. User must define what
eventuality, even after task allotment, is taken
elemental value-adding tasks can be performed
cognizance of. Technically the scheduling
in the facility and what generic components
engine can run autonomously with inbuilt
they produce. They are but few in type - what
capability to raise an alarm for human
changes from order-to-order is are the
intervention only when situation so warrants – a
attributes of generic tasks and components like,
precondition for realizing a true computer
extent to be value-added, cost, wastage,
controlled manufacturing facility.
duration, etc. Table-3 details the number of
generic tasks and components defined in the
first typical installation.

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Table-3: First installation task & component scenario, if time to reschedule exceeds 60
details seconds the system automatically, for such
Number of generic tasks 27 instances, chooses to skip a reschedule to align
with the next minute.
Number of generic
71
components
8 Conclusion
th
Actual system performance as on 19 April Talika PMS is in its infancy. It is just born. Not
2013. many are even aware that such an inexpensive,
easy to use, self-configurable, off-the-shelf
History: The first installation is in its fourth product exist that holds the promise of
successful year with the average mean time positioning any manufacturing facility leagues
between system failure now exceeding 6 apart from its competitors in terms of cost of
months, which in the beginning was around 6 production and reliability of service offered. It is
minutes. That shows how reliable the system just a matter of time before someone makes a
now is. beginning forcing others to adopt similar
systems just to remain in business.
Each time a job is scheduled it is given a running
serial number. It started from ‘1’ and now reads You can know more about Talika PMS by
30900. With 706 currently active jobs, it means visiting www.etalika.in and also download a
30194 jobs were successfully executed by or via free full demo version for evaluation.
the system with each job having about 70
elemental tasks on an average.

How fast it works: The scheduling Engine works
on Dell T310 Power edge server. It has 706
currently active jobs with 49466 elemental tasks
to schedule individually with all the complexity
of decision making already described. Table-4
gives an actual peek of the speed at which the
system works on this date.

Table-4: First installation Scheduling Engine load
Number of active jobs 706
Number elemental tasks to
49466
reckon with
Time to decide what to do
4
NOW (seconds)
Time to reschedule: predict
micro-level future schedule 25
completely (seconds)

Scheduling engine work at a phenomenal speed
of about 1900 tasks / second when it
reschedules, that happens once every minute
making the system live. You can guess the
decision to allot tasks now and knowing effect of
all current decisions as schedule prediction are
independent processes. Time to reschedule is
decided by the number of elemental tasks
present and varies linearly. In worst case

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Exhibit–1: Console Functionality in brief
Console Function Number & Location
Define and estimate all aspects of an JSW is a multi-use console. Sales
orders; persons, Customer Support
Job Study Wizard Simulate or schedule orders; personnel, shop floor Managers
(JSW) Monitor order progress; and Supervisors and even
Manage / Change order execution; customers all can have one for their
CRM functionality. personal use.
It is the Operators’ console. Details of
all allotted tasks flow in real-time to
One WCC can represent one or
these consoles for Operators’ to notify
several or all work center in a
task progress milestones.
Work Center Console facility. Users can tailor the
Also gives details of all tasks already
(WCC) number of WCCs required to cover
done and those lined up for execution
all work centers on the shop floor.
later.
System puts no higher limit.
Valuable machine statistics and many
more helpful features.
Any inputs required from customers?
Customer Interaction As many as personnel involved in
Track, follow-up and notify input when
Console (CIC) managing customer inputs.
they arrive in order of requirement
Preventive Maintenance as well as
unexpected breakdowns engage work
centers and affect the schedule. One
can define preventive maintenance
Maintenance Console schedule in advance and treat it like a
As many as required.
(MTN) maintenance job that can be scheduled
like any other order. This console helps
define a preventive maintenance
program, schedule it and notify its
activities.
Movement and storage of work-in-
progress is a critical function in the
value-adding process and affects the
Material Movement
schedule. We designed a console for As many as required.
Console (MMC)
the person in charge of work-in-progress
that performs all functions as required
in real-time.
Orders may require raw material either
sourced from stores or purchased.
Need for material is decided and driven
Inventory by the scheduling core and thus an
Management entire material management system is As many as required.
Consoles (IMCs) created around the scheduling core.
This one console takes different avatars
depending on what specific inventory
functionality is required.

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Console Function Number & Location
System is fully user configurable and all
this information resides in one logical
database called the factory dB.
However, user must have a means to
Factory dB Manager modify the factory dB without affecting
As many as required.
(FDM) current working system. FDM allows
one to check-out locally a copy of the
factory dB for manipulation / change,
revalidate it and check-in the factory dB
when finalized.
All monetary information generated by
the scheduling core is fetched
Money Management periodically by this console for financial As many as required. Only in
Console (MMM) accounting purposes. One can then concept stage.
build or dove tail this information into
any existing financial ERP system.
Manpower information like past usage,
current manning information being used
and future requirements too flow from
Human Resource As many as required. Only in
the scheduling core. This console is
Consoles (HRC) concept stage.
designed to cull out or control such
information or feed it into any existing
ERP system.

References

[1] D. Ouelhadj, S. Petrovic - A survey of dynamic scheduling in manufacturing systems - Springer Science:
Journal Scheduling (2009) 12: 417–431 - Published online: 28 October 2008

[2] Cowling, P.; Johansson, M. - Production, Manufacturing and Logistics
Using real time information for effective dynamic scheduling - Elsevier: European Journal of Operational
Research 139 (2002) 230–244

[3] Guilherme, E.V.; Herrmann, J.W.; Lin, E. - Rescheduling Manufacturing Systems: A framework of
strategies, policies and methods - Journal of scheduling, Kluwer Academic Publishers, Netherlands

[4] Velaga P., Ph.D. (Scheduling) President, Optisol, 3910 Stony Creek Ln, College Station, Texas 77845 -
Advantages & Difficulties with Drag-and-Drop Operations – Web page link: http://www.optisol.biz/Drag-
and-Drop.htm

[5] Zhang L., Li, X., Gao, L., Yang, Y., Jiang , P. - Predictive/reactive scheduling with uncertain disruptions -
proceedings of the 41st international Conference on Computers & Industrial Engineering P 260-265

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Production planning and scheduling

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