ECD Construction Example
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ECD Construction Example From Weaver
description
ECD Construction Example. From Weaver. Start off with…. The ERD (or extract of) the system. Delivery. Delivery Slot. Delivery Line. Purchase Order Line. Step one. - PowerPoint PPT Presentation
Transcript of ECD Construction Example
ECD Construction Example
From Weaver
Start off with…
• The ERD (or extract of) the system
Delivery Delivery Slot
Delivery LinePurchase Order
Line
Step one
• Identify all data entities which are effected by the event (in this case “Arrange Delivery”) – use the effects from the ELH and/or EEM. Also define the entry point (“Delivery”)
Delivery Delivery Slot
Delivery LinePurchase Order
Line
Step two
• Identify simultaneous effects for the event in question – i.e. effecting more than one occurrence of data entity in different ways . This would give rise to a separate box for each entity role.
Stock[merged]
Stock[resulting]
Please note:This is a disjointexample taken from anotherLDM
Step three
• Identify where an event affects a data entity in one or more mutually exclusive ways – add these effects as options under the data entity. These can be discerned from ELH roles listed in round brackets.
Delivery
Existing Newo o
Step four• Identify data entities affected iteratively (i.e. repeatedly) by the
event.
Delivery
Existingo
Newo
Set ofDelivery lines
Delivery line*
Set ofDelivery slots
Delivery slot*
Purchase Orderline
Step five• Identify one-to-one effects and connect with double-sided arrow
lines. The question to ask for each entity is…For each affected occurrence of this entity, is there a directly related occurrence, or set of occurrences) in any of the other entities that is also affected by the event in question?
Delivery
Existingo
Newo
Set ofDelivery lines
Delivery line*Set of
Delivery slots
Delivery slot* Purchase Order
line
Step six• Add non-updated data entities (none in this example, but…)
Delivery
Existingo
Newo
Set ofDelivery lines
Delivery line*Set of
Delivery slots
Delivery slot* Purchase Order
line
ProductImagine if we required product detailsOne every delivery line (hypothetical)
Step seven (last step)
• List the event data at the ECD entry point. Include entity key and any data fields required for update.
Delivery
Delivery ID Slot ID P.O. No. P.O. Line No. Quantity : :
::::
