Machine-load charts are prepared to assist in production scheduling as well as routing. Machine load charts show the amount of work (in terms of hours, days, or weeks) that has been assigned and scheduled to each machine. groups of identtcal machines or shop departments. They frequently employ Gantt chart to indicate graphically the volume of work ahead of machine/equipment and the amount of capacity available for processing additional work.
Loading and scheduling are designed to assist in the efficient and systematic planning of work. Loading provides a complete and correct information about the number of machines available and their operating characteristics such as speed, capacity, capability etc. This information can be used to calculate the difference between work load and actual capacity and then to determine whether customers order can be completed on due date or not.
Objectives of Loading. The following are some of the objectives of loading:
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(i) to plan new work orders on the basis of spare capacity available. (ii) to balance the work load in a plant.
(iii) to maintain the delivery promises.
(iv) to check the feasibility of production programmes.
(v) they are also used during plant layout for balancing capacity and achieving a uniform flow of work i.e. for eliminating bottlenecks or excess capacity at specific machines and work places.
MACHINE LOADING
Machine radial drill No.9 Week Ending : May 5th Hrs. 40
ORDER
NO. PART NO. OPERATION
LOT SIZE NO. HOURS REQUIRED BALANCE OF LOAD 6993 D 4108 22 600 8 32 6994 D 4507 34 600 12 20 7005* S 470 28 (* 6 hours carried to the next week 1200 26 - 7005 S 470 28 1200 6 32 7008 T 847 16 600 10 22
Fig. 28.6. Machine load chart.
Adjustment to machine overloading and under loading. A machine is overloaded when the total amount of work assigned for a given period is more than that the machine can execute with its current capacity: Depending on bUSiness conditions, overloading can be handled by (I) re-routing work to machines that have unallocated capacity (balance capacity) (it) by operating machine overtime (iii) by subcontracting some work (iv) or by purchasing additional equipment. Underloading can be handled by : (i) acquiring more sales orders (ii) by scheduling work in anticipation of future sales or (iii) as a last resort, by selling the machine.
28.9. DISPATCHING: (RELEASE OFWORK ORDERS)
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Dispatch function executes planning function. It is concerned with getting the work started. Dispatching ensures that the plans are properly implemented. Dispatch function authorizes the workers to do the work. The information collected In scheduling and route sheet is transmitted into the orders. The prepared orders are released to the concerned departments for actual implementation. Every care is taken to issue clear cut instructions, in a simple form in written sheets which can be easily understood and correctly implemented by the concerned persons and there is no confusion.
In brief the activities of dispatching may be listed as below:
(1) Issue of Move orders. Move orders are issued to movement personnel giving instructions regarding movement of raw materials from stores to the manufacturing floor, or from machine to machine as the case may be.
(2) Issue of Tool orders. These are issued to the tool department to collect and make ready tools, jigs and fixtures in advance of the time at which the operation will commence.
(3) Issue of Job orders (job tickets). Job orders are issued to the operations or job foremen for starting the work. Job orders are prepared in accordance with dates and time previously planned and entered on the machine loading charts, route sheets and progress control sheets.
(4) Issue of Inspection orders. Inspection orders are issued to the inspection personnel giving instructions regarding Inspection centres, type of inspection required at different stages of operations, gauges to be used etc.
(5) Issue of drawings, time tickets, instruction cards and other necesslu-Y information. These are issued to the operators, so that they will carry out their work smoothly without any difficulty.
(6) Issue of store orders. These orders are issued to the store to supply the raw material against the proper authorizallon.
(7) Issue of orders to finished product stores. These orders instruct the finished product store for collccting the finished products on determined lines.
In addition to any issue of the orders mentioned above the dispatching
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function also includes the following activities:
(8) Collection of time tickets, drawings and instruction cards for all completed operations or jobs.
(9) Recording time of beginning and completing. Jobs, and calculating duration, forwarding complete records to production department and time card to pay roll department.
(10) Recording and reporting idle time of machines and operators. Centralised ancl Decentraiised Dispatching
In a centralised dispatch system, a central dispatching department orders d'ireetly to work stations. It maintains full record of capacity of each equipment and work load against each machine. The orders are given to the .shop supervisor, who runs the machines accordingly. In most of the cases the supervisor can give suggestions as regards loading of men and machines under him.
The advantages of the centralized system are: (I) A greater degree of overall control can be achieved.
(2) Effective co-ordination between different facilities is possible. (3) It has a greater flexibility.
(4) Progress of the orders can be readily assessed at any time because all the information is available at the central place.
(5) There is effective and better utilization of manpower and machinery.
In a decentralised system the shop supervisor performs the dispatch functions. He decides the sequence of different orders and materials to each equipment and worker. He is required to complete the work wilhin the prescribed duration. In case he suspects delay with due reasons of the same he informs the production control department accordingly.
The advantages of the decentralized dispatching system are :
(I) Shop supervisor has a better knowledge of his shop, therefore he can allot the work to the most appropriate worker and the machine.
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(2) Elaborate reports and duplication of postings can be reduced. (3) It is easy to solve day-to-day problems.
(4) Communication gap is reduced. 28.10. PRODUCTION CONTROL
Production control is one of the most important and fundamental functions of an enterprise. It ensures the desired output of specified quality at the prescribed time in the most economical manner to meet the sales requirements. The production control directs and regulates all the activities of a production process. It verifies whether the activities are going in accordance with production plan or not. Control is some management process which constrains events to follow plans. It is some sort of dynamic activity controlling the production cycle to ensure that facilities and the personnel are economically utilised and that the products are manufactured within minimum possible time and economically.
Production control provides the foundation on which most of the other industrial controls are based. It is the hall mark of production efficiency. It is the pivot around which the success of production revolves. It is a necessity and not luxury; a profitable investment and not an expense.
Definition of Production Control
According to Mary Cushing Niles, "control is maintaining a balance in activities towards a goal or set of goals evolved during production planning". Planning only outlines some course of action whereas control is an execution process involving standardization, evaluation and corrective actions.
According to Fayol, "control consists in verifying whether everything occurs in conformity with the adopted plan and established principles. The objective of control is to point out weakness or shortcomings if any, in order to rectify ~hem and prevent recurrence. It operates on everything viz., material, equipment, men, operations etc. For control to be effective it must be applied within reasonable time and be followed-up sanctions."
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Thus production control is some scientific procedure to regulate an ordely flow of material and coordinate various production operations to accomplish the objective of producing the required quantity of the desired product, of the required quality, at the required time by using the best and cheapest method i.e. to altain highest efficiency in production.
Alternately, production control is the function of management which plans, directs and controls the material supply and processing activities of an enterprise; so that specified products are produced by specified methods to meet an approved sales programme. It ensures that the activities are carried in such a way that the available labour and capital are used in the best possible way.
The control of production is necessary to ensure that the production schedules are· being met and the job will be delivered as per the pre-decided plans to satisfy the requirements of the customers. Production control involves an information feed back mechanism and a system of corrective action. Production control follows up the scheduled plans, compares the actual output with the planned one, and points out deviations, if any, so that the same can be corrected through the adjustments of men, materials and machines.
In brief, a production control system: . (i) receives work progress reports,
(i) compares them with the scheduled plans, (iii) removes causes of delays in production, (iv) modifies the schedules or plant capacities, and (v) expedites the work.
Objectives of Production Control
Production control provides the foundation on which most of the other industrial controls are based.
Production control is the hall mark of production efficiency. It is the pivot around which the success of production revolves. Thus, the success of an enterprise greatly depends on the performance of its production control department. The
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production control department generally has to perform the following functions: (i) To organise production schedule in conformity with the demand forecast.
(ii) To have optimum utilization of resources in such a way that the cost of production is minimised and delivery date is maintained.
(iii) Determination of economic production runs with a view to reduce setup costs. (iv) Proper co-ordination of the operations of various sections/departments
responsible for production.
(v) To ensure regular and timely supply of raw material at the desired place and of prescribed quality and quantity to avoid delays in production.
(vi) Perform inspection of semi-finished and finished goods and use quality control techniques to ascertain that the produced items are of required quality.
Thus the fundamental objective of production control is to regulate and control the various operations of production process in such a way that the items are produced of right quality in right quantity at the right time with minimum effort and cost.
Follow-up or control phase:
Follow up is a most important step of production control. As already described, once the work has been started in the activity, it is necessary to evaluate continuolJsly the progress in terms of the plan so that deviations can be detected and corrected as quickly as possible.
The follow-up phase accordingly consists of : I. Progress reporting
(a) Data collection b) Data interpretation 2. Corrective action.