Posts

Poka Yoke

Poka Yoke:    A design approach to quality that places the responsibility for preventing defects within the design of the product and/or production process. Approaches:  Design- Within the product design specifications replace those specs which require defect prone Processes/components with those that require non-defect prone Processes/ components. Processes/fixture- Within manufacturing replace those Processes/fixtures which are defect prone with those that are not. Example:   Design: "We have been disconnected"         An electronics manufacturer had three circuit cards connected by flex cables which were hand soldered into the boards. A high scrap rate was noticed with the boards. Occasionally operators would burn the boards while soldering. Some cables were snapped off during integration. Often test failures required the cables be removed for diagnosis and boards would be damaged during rework. The boards were redesigned with telephone jacks w...
Post a Comment
Read more

QUALITY AT THE SOURCE

Quality at the source:  A philosophy that places the responsibility for meeting customer specifications and standards at the point of manufacture. APPROACH:  1) Source inspection for purchased components. 2) Operator's self inspect their work as well as inspecting the work of previous operator's. 3) Poke- yoke designed manufacturing devices , Processes and product's. DISCUSSION: Quality at the source concept are based on a theoretically ideal scenario. However by using these principles and concept significant quality improvement can be made. The idea is to cut off mistakes at the earliest possible point. Requirements in plant applications:  1) The employees must be introduced to the concept. 2) Stage by stage accept/reject criteria must be set. 3) Employees must be trained. 4) Rework should be internalized in the work group, no paper, no engineers, no quality assurance. 5) Best results achieved in one piece flow cellular manufact...
Post a Comment
Read more

VALUE STREAM MAPPING

Image
VALUE STREAM MAPPING: The process of identifying and charting the flows of information, processes, and physical goods across the entire supply chain form the raw material supplier to the possession of the customer. Value stream mapping is a basic planing tool for identifying wastes, designing solutions and communicating lean concepts. BENEFITS: 1) Highlighted dependencies. 2) Identified opportunities for the application of specific tools and strategies. 3) Improve understanding of highly complex systems. 4) Synchronized and prioritized Continuous improvement activities. OBJECTIVE OF VALUE STREAM MAPPING: 1) Visualisation of material and information flows. 2) Facilitate the identification and elimination of waste and the sources of waste. 3) Support the prioritization of continuous improvement activities at the plant and value stream levels. 4) Support constraint analysis. 5) Provide a common language for process evaluation. ORGANIZATION OF VA...
Post a Comment
Read more

TYPES OF LEAN WASTE

LEAN WASTE:  Seven type of waste are: 1) Over production 2) Wait time 3) Transportation 4) Processing 5) Inventory 6) Motion 7) Defect # EXPLANATION OF ALL TYPES OF WASTE: 1) OVER PRODUCTION: Definition: Producing more than is needed, faster than needed or before needed is known as over production. CHARACTERISTICS:  1) Batch processing. 2) Building ahead. 3) Byzantine inventory management. 4) Excess equipment. 5) Excess storage racks. 6) Large lot sizes. 7) Outside storage. CAUSES: 1) Automation in the wrong places. 2) Cost accounting practices. 3) Incapable processes. 4) Just in case reward system. 5) Low uptimes. 6) Poor planning. Example: Units which were produced in anticipation of future demand are often scrapped due  to configuration changes. 2) WAIT TIME: Definition: Idle time that occurs when codependent events are not fully synchronized. CHARACTERISTICS:  1) Idle operators waiting for equipment. 2) Lack of operator concern for equipment breakdown. ...
Post a Comment
Read more