PPC - PRODUCTION, PLANNING AND CONTROL
INTRODUCTION
PRODUCTION
PLANNING IS A MANAGERIAL FUNCTION WHICH IS MAINLY CONCERNED WITH THE FOLLOWING
IMPORTANT ISSUES:
- WHAT PRODUCTION
FACILITIES ARE REQUIRED?
- HOW THESE
PRODUCTION FACILITIES SHOULD BE LAID DOWN IN THE SPACE AVAILABLE FOR
PRODUCTION? AND
- HOW THEY SHOULD BE USED TO PRODUCE THE DESIRED PRODUCTS AT THE DESIRED RATE OF PRODUCTION?
BROADLY
SPEAKING, PRODUCTION PLANNING IS CONCERNED WITH TWO MAIN ASPECTS: (I) ROUTING
OR PLANNING WORK TASKS (II) LAYOUT OR SPATIAL RELATIONSHIP BETWEEN THE
RESOURCES. PRODUCTION PLANNING IS DYNAMIC IN NATURE AND ALWAYS REMAINS IN FLUID
STATE AS PLANS MAY HAVE TO BE CHANGED ACCORDING TO THE CHANGES IN
CIRCUMSTANCES.
PRODUCTION
CONTROL IS A MECHANISM TO MONITOR THE EXECUTION OF THE PLANS. IT HAS SEVERAL
IMPORTANT FUNCTIONS:
- MAKING SURE THAT
PRODUCTION OPERATIONS ARE STARTED AT PLANNED PLACES AND PLANNED TIMES.
- OBSERVING
PROGRESS OF THE OPERATIONS AND RECORDING IT PROPERLY.
- ANALYZING THE
RECORDED DATA WITH THE PLANS AND MEASURING THE DEVIATIONS.
- TAKING IMMEDIATE
CORRECTIVE ACTIONS TO MINIMIZE THE NEGATIVE IMPACT OF DEVIATIONS FROM THE
PLANS.
- FEEDING BACK THE
RECORDED INFORMATION TO THE PLANNING SECTION IN ORDER TO IMPROVE FUTURE
PLANS.
TABLE 1: PRODUCTION PLANNING AND CONTROL FUNCTIONS
FUNCTIONS
|
ISSUES TO BE COVERED
|
PRODUCT DESIGN& DEVELOPMENT
|
CUSTOMER NEEDS, MARKET NEEDS,
AVAILABILITY OF SIMILAR PRODUCT, DEMAND-SUPPLY GAP, FUNCTIONAL ASPECTS,
OPERATIONAL ASPECTS, ENVIRONMENTAL ASPECTS ETC.
|
DEMAND FORECASTING
|
QUANTITY, QUALITY, DEMAND PATTERN.
|
CAPACITY PLANNING
|
NO. OF MACHINES, NO. OF TOOLING,
WORKERS, NO.OF FLOW LINES, QUANTITY, QUALITY AND RATE OF PRODUCTION, DEMAND
PATTERN.
|
EQUIPMENTS SELECTION &
MAINTENANCE
|
NO. OF MACHINES, TYPE OF M/C, QUALITY
ASPECTS, QUANTITY ASPECTS, RATE OF PRODUCTION, COST OF
EQUIPMENTS, SUPPORT FROM THE SUPPLIER, MAINTENANCE POLICY, AND STORAGE
OF SPARE PARTS.
|
TOOLING SELECTION
|
COMPACTABILITY BETWEEN W/C STEELS,
NO. OF TOOLS, THEIR COST, THEIR MATERIAL ETC, STORAGE POLICY.
|
MATERIAL SELECTION & MANAGEMENT
|
TYPES, SPECIFICATION, QUALITY ASPECT,
QUANTITY ASPECT, COST, SUPPLIES REPUTATION , LOT SIZE, INVENTORY LEVELS,
SETUP COST, MODE OF TRANSPORTATION ETC.
|
PROCESS PLANNING
|
GENERATION OF MANUFACTURE
INSTRUCTION, SELECTION OF M/C, TOOLS, PARAMETERS, SEQUENCE
ETC.
|
LOADING
|
DIVISION OF WORK LOAD, ASSIGNMENT OF
TASKS, UNIFORM LOADING, MATCHING BETWEEN CAPABILITY & CAPACITY WITH JOB
REQUIREMENTS.
|
ROUTING
|
PATH SELECTION FOR MATERIAL MOVEMENT
AS PER THE PROCESS PLAN AND LOADING, MINIMUM MATERIAL HANDLING AND WAITING
TIME.
|
SCHEDULING
|
TIME BASED LOADING, START AND FINISH
TIMES, DUE DATES, DISPATCHING RULES, RE-SCHEDULING.
|
EXPEDITING
|
OPERATION SCHEDULING AND ORDER AND
PROGRESS REPORTING.
|
TYPES OF PRODUCTION SYSTEMS
A
PRODUCTION SYSTEM CAN BE DEFINED AS A TRANSFORMATION SYSTEM IN WHICH A SALEABLE
PRODUCT OR SERVICE IS CREATED BY WORKING UPON A SET OF INPUTS. INPUTS ARE
USUALLY IN THE FORM OF MEN, MACHINE, MONEY, MATERIALS ETC. PRODUCTION SYSTEMS
ARE USUALLY CLASSIFIED ON THE BASIS OF THE FOLLOWING:
- TYPE OF PRODUCT,
- TYPE OF
PRODUCTION LINE,
- RATE OF
PRODUCTION,
- EQUIPMENTS USED ETC.
THEY ARE BROADLY CLASSIFIED
INTO THREE CATEGORIES:
- JOB SHOP
PRODUCTION
- BATCH PRODUCTION
- MASS PRODUCTION
JOB PRODUCTION
IN THIS
SYSTEM PRODUCTS ARE MADE TO SATISFY A SPECIFIC ORDER. HOWEVER THAT ORDER MAY BE
PRODUCED-
- ONLY ONCE
- OR AT IRREGULAR
TIME INTERVALS AS AND WHEN NEW ORDER ARRIVES
- OR AT REGULAR TIME INTERVALS TO SATISFY A CONTINUOUS DEMAND
THE
FOLLOWING ARE THE IMPORTANT CHARACTERISTICS OF JOB SHOP TYPE PRODUCTION SYSTEM:
- MACHINES AND
METHODS EMPLOYED SHOULD BE GENERAL PURPOSE AS PRODUCT CHANGES ARE QUITE
FREQUENT.
- PLANNING AND
CONTROL SYSTEM SHOULD BE FLEXIBLE ENOUGH TO DEAL WITH THE FREQUENT CHANGES
IN PRODUCT REQUIREMENTS.
- MAN POWER SHOULD
BE SKILLED ENOUGH TO DEAL WITH CHANGING WORK CONDITIONS.
- SCHEDULES ARE
ACTUALLY NON EXISTENT IN THIS SYSTEM AS NO DEFINITE DATA IS AVAILABLE ON
THE PRODUCT.
- IN PROCESS
INVENTORY WILL USUALLY BE HIGH AS ACCURATE PLANS AND SCHEDULES DO NOT
EXIST.
- PRODUCT COST IS
NORMALLY HIGH BECAUSE OF HIGH MATERIAL AND LABOR COSTS.
- GROUPING OF
MACHINES IS DONE ON FUNCTIONAL BASIS (I.E. AS LATHE SECTION, MILLING
SECTION ETC.)
- THIS SYSTEM IS
VERY FLEXIBLE AS MANAGEMENT HAS TO MANUFACTURE VARYING PRODUCT TYPES.
- MATERIAL
HANDLING SYSTEMS ARE ALSO FLEXIBLE TO MEET CHANGING PRODUCT REQUIREMENTS.
BATCH PRODUCTION
BATCH
PRODUCTION IS THE MANUFACTURE OF A NUMBER OF IDENTICAL ARTICLES EITHER TO MEET
A SPECIFIC ORDER OR TO MEET A CONTINUOUS DEMAND. BATCH CAN BE MANUFACTURED
EITHER-
- ONLY ONCE
- OR REPEATEDLY AT
IRREGULAR TIME INTERVALS AS AND WHEN DEMAND ARISE
- OR REPEATEDLY AT REGULAR TIME INTERVALS TO SATISFY A CONTINUOUS DEMAND
THE
FOLLOWING ARE THE IMPORTANT CHARACTERISTICS OF BATCH TYPE PRODUCTION SYSTEM:
- AS FINAL PRODUCT
IS SOMEWHAT STANDARD AND MANUFACTURED IN BATCHES, ECONOMY OF SCALE CAN BE
AVAILED TO SOME EXTENT.
- MACHINES ARE
GROUPED ON FUNCTIONAL BASIS SIMILAR TO THE JOB SHOP MANUFACTURING.
- SEMI AUTOMATIC,
SPECIAL PURPOSE AUTOMATIC MACHINES ARE GENERALLY USED TO TAKE ADVANTAGE OF
THE SIMILARITY AMONG THE PRODUCTS.
- LABOR SHOULD BE
SKILLED ENOUGH TO WORK UPON DIFFERENT PRODUCT BATCHES.
- IN PROCESS
INVENTORY IS USUALLY HIGH OWING TO THE TYPE OF LAYOUT AND MATERIAL
HANDLING POLICIES ADOPTED.
- SEMI AUTOMATIC MATERIAL
HANDLING SYSTEMS ARE MOST APPROPRIATE IN CONJUNCTION WITH THE SEMI
AUTOMATIC MACHINES.
- NORMALLY
PRODUCTION PLANNING AND CONTROL IS DIFFICULT DUE TO THE ODD SIZE AND NON
REPETITIVE NATURE OF ORDER.
MASS PRODUCTION
IN MASS
PRODUCTION, SAME TYPE OF PRODUCT IS MANUFACTURED TO MEET THE CONTINUOUS DEMAND
OF THE PRODUCT. USUALLY DEMAND OF THE PRODUCT IS VERY HIGH AND MARKET IS GOING
TO SUSTAIN SAME DEMAND FOR SUFFICIENTLY LONG TIME.
THE
FOLLOWING ARE THE IMPORTANT CHARACTERISTICS OF MASS PRODUCTION SYSTEM:
- AS SAME PRODUCT
IS MANUFACTURED FOR SUFFICIENTLY LONG TIME, MACHINES CAN BE LAID DOWN IN
ORDER OF PROCESSING SEQUENCE. PRODUCT TYPE LAYOUT IS MOST APPROPRIATE FOR
MASS PRODUCTION SYSTEM.
- STANDARD METHODS
AND MACHINES ARE USED DURING PART MANUFACTURE.
- MOST OF THE EQUIPMENT ARE SEMI AUTOMATIC OR AUTOMATIC IN NATURE.
- MATERIAL
HANDLING IS ALSO AUTOMATIC (SUCH AS CONVEYORS).
- SEMI SKILLED
WORKERS ARE NORMALLY EMPLOYED AS MOST OF THE FACILITIES ARE AUTOMATIC.
- AS PRODUCT FLOWS
ALONG A PRE DEFINED LINE, PLANNING AND CONTROL OF THE SYSTEM IS MUCH
EASIER.
- COST OF
PRODUCTION IS LOW OWING TO THE HIGH RATE OF PRODUCTION.
- IN PROCESS
INVENTORIES ARE LOW AS PRODUCTION SCHEDULING IS SIMPLE AND CAN BE
IMPLEMENTED WITH EASE.
REFERENCES: - www.nptel.iitm.ac.in
I read lot of articles and really like this article. This information is definitely useful for everyone in daily life. Fantastic job.
ReplyDeleteB Tech in quality management
Part time B.tech in program
B.Tech in Industrial Engineering
study tips good one of this article...
ReplyDeleteAluminium Scaffolding Price