The entire system or process of doing work should be studied before undertaking a thorough investigation of a specific operation in the process. Such an over-all study will ordinarily include an analysis of each step in the manufacturing process or system. Process Analysis Tools ;operation process chart ; Flow process chart Flow diagram OPERATION PROCESS CHART The operation process chart shows the chronological sequence of all operations, inspections, time allowances, and materials used in a manufacturing or business process, from the arrival of raw material to the packaging of the knishes product.
The chart depicts the entrance of all components and subassembly to the main assembly. Two symbols are used in constructing the operation process Chart : an operation and an inspection. FLOW PROCESS CHART The flow process chart is a device for recording a process in a compact manner, as a means of better understanding it and improving it. The chart represents graphically the separate steps or events that occur during the performance of a task or doing a series of actions. The chart usually begins with the raw material entering the factory and follows it through every step.
The process chart symbols : The American Society of Mechanical Engineers (SAME) has established the five standard symbols are described As follows: Operation An operation occurs when an object is intentionally changed in one or more of its characteristics. An operation represents a major step in the process and usually occurs at a machine or work station. Transportation A transportation occurs when an object is moved from one place to another, except when the movement is an integral part of an operation or and inspection.
Inspection An inspection occurs when an object is examined for identification or is compare with a standard as to quantity or quality. Delay A delay occurs when the immediate performance of the next planned action does not take place. Storage A storage occurs when an object is kept under control such that its withdrawal requires authorization. Combined symbols Two symbols may be combined when activities are performed at the same work place or when they are performed concurrently as one activity. Example Represents a combined operation and inspection.
The Process chart symbols Types of Flow Process Chart: – Product or Material type – Worker (Man) type Machine type Process chart (Material) for preparation of direct mail Flow process chart (worker) for field inspection of LUG. FLOW DIAGRAM A pictorial representation of the layout of floors and buildings, showing the locations of all activities on the flow process chart, is a flow diagram. The flow diagram is a helpful supplement to the flow process chart because it indicates backtracking and possible traffic congestion areas, and it facilitates developing an idea plant layout.
Flow diagram of the old layout of a group of operations on The Grand rifle. Recoding Buffing Wheels with Emery In large factories where heavy polishing and buffing operations are required, it is customary to recoated buffing wheels with emery in the plant, thus keeping a supply of fresh wheels always available. The wheels are made of layers of fabric sewed together, and their average weight is 40 pounds. They vary in diameter from 18 to 24 inches, and width of face from 3 to 5 inches. The circumference or face of wheel is coated with glue and emery dust.
The first coat of glue is allowed to set approximately one-half hour before the second coat is applied. The temperature in the room where the wheels are rued is maintained between 80 to 900, and the humidity Is also controlled. Buffing wheel Original Method The circumference of the wheel was coated with glue and then roll by hand through a shallow trough filled with emery dust, thus coating the wheel. After the glue had dried, a second coat of glue and emery dust was applied in a similar manner. The wheels were then hauled to a drying oven.
And hung on tracks in the oven until the glue was thoroughly dry. Operator applies glue to circumference of worn wheel by mean of a brush Old method of recreating wheel. Operator rolls glue-covered heel back and forth in trough containing emery dust. Flow Process Chart (original method) Flow diagram of old method of recreating buffing wheels with emery. The following questions might be asked about this Job: ; Why coat the wheels by hand? ; Why handle the wheels so often? ; Could the wheels be coated on the first floor instead of on the second?
Improved Method OH special coating machine was built, making it possible to apply the glue and emery to the wheel in one operation with much less time and effort than by the old method. ;Because this machine was located on the first floor teen the storage area and the drying oven, it was unnecessary to move the wheels to the second floor. ;special truck racks were used instead of regular platform trucks, eliminate much unnecessary handling of wheels. Improved Method (continue) ;The coated wheels remained on the truck racks while in the drying oven.