DFA, DFM & DFE

The standard time contains much more information than only the normalised labour time. It has vital information which is used for productivity improvement and design engineering.   The smart way is to define the waste in labour time as the extra time needed when mounting an ideal assembly.    With a statistical calculation we can specify mathematically the ideal shape or weight of a perfect part which is also called the added value and which will tell us when design losses or mudas are occurring.

 

3 different losses are recognisable in Design engineering.
	DFA - Design for assembly Labour losses caused by the shape or the weight of a product are called design for assembly or abbreviated DFA.   The target is to visualise these difficulties one experiences to mount a part.    DFA losses are always related to parts and not to tooling or using the tool.     A better product to mount is a result of parts which are easier to take and place.  Each part has a calculateable DFA which we express in lost time per piece. Vrex marks DFA in a yellow colour and benchmarks it or measures it in seconds per part.
	DFA - Design for assembly Losses caused by the use of tooling to mount a part are called design for manufacturing.  Tools are selected in function of cost or labour time to mount the product.  DFM time is easier to manipulate and to improve than DFA because innovative tooling can always be found. DFM is a visualisation of a specific DFA.   The advantage of DFM is that the design of the product remains constant while achieving improvements. Each part has a calculate able DFM which we express in lost time per piece. Vrex marks DFM in a orange colour and measures it in seconds per part.
	DFE - Design for efficiency A drastic reduction of the labour time can be achieved by minimising the count of parts in the product structure.   This happens by eliminating fixation parts which have no other function than to connect the basic parts.   In other words  we want to minimise them with an equivalent connection quality of the basic parts to obtain a lower production time.    DFE expresses the overuse of fixation parts in a assembly.  But because DFE changes affect the product structure they demand mostly a complete redesign which is expensive and not always possible. Vrex marks DFE as a percent of the totals parts in a product. 100% mains no fixation parts.
It is an ongoing concern of the industrial engineer to measure and to overcome or to minimise these losses.   At the end there is only one correct method to obtain a lean factory "Measuring is knowledge of your product and will lead to the best plant with a acceptable infrastructure" The Vrex software suite defines all improvable losses in a methodology which we call the "The 7 mudas of productivity"