Types of manufacturing/production system Types of Production system Manufacturing System Service SystemContinuous Production Intermittent Production Batch Production Job Production Mass production( Flow) Processing Production
Basic Types of Production Processes (1) Intermittent Production SystemProduction is performed on a start-and-stop basis, such as for themanufacture of made-to-order products.Batch Production System•Highly specialized Human resource is required•Highly specialized multi tasking machines•Machines are shared.•Production in batches•Production lots are based on customer demand or order.•No single sequence of operationFinished goods are heterogeneousJob production system In this system, the goods are produced according to definitecustomers order and all manufacturing set ups depend on thereceipt of specific item in printing of example many different jobs goon at any one time.(2) Continuous Production Processes–A production process, such as those used by chemical plants orrefineries, that runs for very long periods without the start-and-stopbehavior associated with intermittent production.–Enormous capital investments are required for highly automatedfacilities that use special-purpose equipment designed for highvolumes of production and little or no variation in the type ofoutputs.
Mass ProductionA special type of intermittent production process usingstandardized methods and single-use machines to produce longruns of standardized items.Mass Production System (Flow)Continuous Production•Anticipation of demand•May not have uniform production•Standardized Raw material•Big volume of limited product line•Standard facility- high standardization.•Fixed sequence of operation•Material handling is easier•High skilled operator not required•More Human problem is foreseen•Huge investment.•High raw material inventory.Processing Production System In this process are inter linked production is carried oncontinuously through a uniform and standardized sequence ofoperation. This type of production is used in bulk processing ofcrude oil into petroleum, kerosene and diesel etc.
Operation schedulingMaster Production scheduling, detailed scheduling, facility loadingsequencing operations, priority sequencing techniques, linebalancing and line of balance (LOB),(Problems in Priority sequencing, Johnson’s rule and LineBalancing)Scheduling • Scheduling: Establishing the timing of the use of equipment, facilities and human activities in an organization • Effective scheduling can yield – Cost savings – Increases in productivityObjectives • customer satisfaction • optimization of cost • increase in efficiency • reduced variances in the transformation process • employee focus in schedulingTypes of scheduling 1. master scheduling 2. parts scheduling 3. machine loading schedulingPrinciples of schedulingPrinciple of optimum task sizePrinciple of the optimum production planPrinciple of the optimum operation sequence
Gantt chart Gantt chart - used as a visual aid for loading and scheduling Work Mon. Tues. Wed. Thurs. Fri. Center 1 Job 3 Job 4 2 Job 3 Job 7 3 Job 1 Job 6 Job 7 4 Job 10Job Sequencing Rules • Sequencing: Determine the order in which jobs at a work center will be processed. • Workstation: An area where one person works, usually with special equipment, on a specialized job. • Priority rules: Simple heuristics used to select the order in which jobs will be processed. • Job time: Time needed for setup and processing of a job.Priority Rules • FCFS - first come, first served • SPT - shortest processing time • EDD - earliest due date • CR - critical ratio • S/O - slack per operation • Rush - emergency
Average Average Average Number of Flow Time Tardiness Jobs at theRule (days) (days) Work CenterFCFS 20.00 9.00 2.93SPT 18.00 6.67 2.63EDD 18.33 6.33 2.68CR 22.17 9.67 3.24Two Work Center Sequencing • Johnson’s Rule: technique for minimizing completion time for a group of jobs to be processed on two machines or at two work centers. • Minimizes total idle time • Several conditions must be satisfiedJohnson’s Rule Conditions • Job time must be known and constant • Job times must be independent of sequence • Jobs must follow same two-step sequence • Job priorities cannot be used • All units must be completed at the first work center before moving to secondRule Optimum Sequence 1. List the jobs and their times at each work center 2. Select the job with the shortest time 3. Eliminate the job from further consideration 4. Repeat steps 2 and 3 until all jobs have been scheduled