SCHEDULING
Dr. SHAILAJA B
ASSOCIATE PROFESSOR
• Scheduling can be defined as “prescribing of when
and where each operation necessary
to manufacture the product is to be performed.”
OR
• It is also defined as “establishing of times at which to
begin and complete each event or
operation comprising a procedure”. The
principle aim of scheduling is to plan the
sequence of work so that production can be
systematically arranged towards the end of
completion of all products by due date.
• The principle of optimum task size : Scheduling tends to
achieve maximum efficiency when the task sizes
are small, and all tasks of same order of magnitude.
• Principle of optimum production plan: The planning
should be such that it imposes an equal load on all
plants.
• Principle of optimum sequence: Scheduling tends to
achieve the maximum efficiency when the work is
planned so that work hours are normally used
in the same sequence.
1. Forward scheduling
• Forward scheduling is
commonly used in job
shops where customers
place their orders on
“needed as soon as possible”
basis.
• Forward scheduling determines
start and finish times of
next priority job by
assigning it the earliest
available time slot and
from that time, determines
when the job will be finished
in that work centre.
2. Backward scheduling
• It is often used in assembly
type industries and
commit
in advance to specific
delivery dates. Backward
scheduling determines the
start and finish times for
waiting jobs by assigning
them to the latest available
time slot that will enable
each job to be completed
just when it is due, but done
before.
• The scheduling methodology depends upon the type of
industry, organization, product, and level of
sophistication required. They are:
1. Charts and boards,
2. Priority decision rules, and
3. Mathematical programming methods.
• Gantt charts and associated scheduling boards have been extensively
used scheduling devices in the past, although many of the charts
are now drawn by computer. Gantt charts are extremely
easy to understand and can quickly reveal the current or
planned situation to all concerned. They are used in several forms,
namely,
• (a) Scheduling or progress charts, which depicts the sequential
schedule;
• (b) Load charts, which show the work assigned to a group of
workers or machines; and
• (c) Record a chart, which are used to record the actual operating
times and delays of workers and machines.
• Priority decision rules are simplified guidelines for
determining the sequence in which jobs will be done.
• Scheduling is a complex resource allocation problem. Firms process
capacity, labour skills, materials and they seek to allocate their
use so as to maximize a profit or service objective, or perhaps
meet a demand while minimizing costs.
The following are some of the models used in scheduling and
production control.
• Linear programming model: Here all the constraints and
objective functions are formulated as a linear equation
and then problem is solved for optimality. Simplex
method, transportation methods and assignment
method are major methods used here.
• PERT/CPM network model: PERT/CPM network is the
network showing the sequence of operations for a project
Scheduling is done in all the
activities of an organization
i.e., production, maintenance
etc. Therefore,
scheduling is used
all the
methods and techniques
of
Production and operation management : - N. Suresh & S. Anil
Kumar

PRODUCTION OPERATIONS MANAGEMENT SCHEDULING.pptx

  • 1.
  • 2.
    • Scheduling canbe defined as “prescribing of when and where each operation necessary to manufacture the product is to be performed.” OR • It is also defined as “establishing of times at which to begin and complete each event or operation comprising a procedure”. The principle aim of scheduling is to plan the sequence of work so that production can be systematically arranged towards the end of completion of all products by due date.
  • 3.
    • The principleof optimum task size : Scheduling tends to achieve maximum efficiency when the task sizes are small, and all tasks of same order of magnitude. • Principle of optimum production plan: The planning should be such that it imposes an equal load on all plants. • Principle of optimum sequence: Scheduling tends to achieve the maximum efficiency when the work is planned so that work hours are normally used in the same sequence.
  • 4.
    1. Forward scheduling •Forward scheduling is commonly used in job shops where customers place their orders on “needed as soon as possible” basis. • Forward scheduling determines start and finish times of next priority job by assigning it the earliest available time slot and from that time, determines when the job will be finished in that work centre. 2. Backward scheduling • It is often used in assembly type industries and commit in advance to specific delivery dates. Backward scheduling determines the start and finish times for waiting jobs by assigning them to the latest available time slot that will enable each job to be completed just when it is due, but done before.
  • 6.
    • The schedulingmethodology depends upon the type of industry, organization, product, and level of sophistication required. They are: 1. Charts and boards, 2. Priority decision rules, and 3. Mathematical programming methods.
  • 7.
    • Gantt chartsand associated scheduling boards have been extensively used scheduling devices in the past, although many of the charts are now drawn by computer. Gantt charts are extremely easy to understand and can quickly reveal the current or planned situation to all concerned. They are used in several forms, namely, • (a) Scheduling or progress charts, which depicts the sequential schedule; • (b) Load charts, which show the work assigned to a group of workers or machines; and • (c) Record a chart, which are used to record the actual operating times and delays of workers and machines.
  • 8.
    • Priority decisionrules are simplified guidelines for determining the sequence in which jobs will be done.
  • 9.
    • Scheduling isa complex resource allocation problem. Firms process capacity, labour skills, materials and they seek to allocate their use so as to maximize a profit or service objective, or perhaps meet a demand while minimizing costs. The following are some of the models used in scheduling and production control. • Linear programming model: Here all the constraints and objective functions are formulated as a linear equation and then problem is solved for optimality. Simplex method, transportation methods and assignment method are major methods used here. • PERT/CPM network model: PERT/CPM network is the network showing the sequence of operations for a project
  • 10.
    Scheduling is donein all the activities of an organization i.e., production, maintenance etc. Therefore, scheduling is used all the methods and techniques of
  • 11.
    Production and operationmanagement : - N. Suresh & S. Anil Kumar