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 : :

::::