Can I control duplicates on my hierarchy diagram?

Duplicates In a Hierarchy?

In the case of a standard hierarchy in a book, it is unlikely you’d see duplicates. Chapter 1 may contain paragraph 1 and sub paragraph 1.1. (A complete reference of 1.1.1).  Paragraph 1 in chapter 2 would be 2.1 and therefore, even though paragraph 1 is a duplicate number the full identity is unique. However, in an engineering context, it is much more likely that information will be referenced in more than one place. Hierarchy duplicates are not unusual for referenced information. After all, it is much better to store the information once and use it many times. This is one of the major benefits of a Requirements Management tool. Imagine each component that has to meet a certain design standard. It makes complete sense to relate each part to the  standard, rather than copying the standard numerous times. In this regard the hierarchy contains duplicates. For each part that is drilled down many  components will end up with the same standard at a lower level of the hierarchy.

Linked Hierarchical Information

The following example shows the expansion of a component (Pump) into the sub components (we’ve followed a link type of SUB-PART). The diagram shows that two of the components have to comply with specific flammability requirements. Both Pump Housing and Pump Electrical Control are linked to REF-13 for Flammability. In turn this has lower elements of Smoke  generation for plastics and flammability of Cables.

The diagram illustrates that REF-1.3 is a duplicate by the small square in it’s NE corner.

How to control expansion of hierarchy duplicates on a HID
HID Expansions

Controlling Expansion of Hierarchy Duplicates

The Hierarchy Diagram Properties dialog has an option to control whether items seen as duplicates are expanded to further levels. Here the Expand Duplicates option is unticked which is why the user does not see REF-12 and REF-14 expanded below it.

Can I control the shape of a HID?

Hierarchy Diagram Output Control

Yes you can control the shape of a HID (Hierarchy Diagram). In the hid properties you can control the shape and data shown in your HID.

The cross reference links between each item control the connections shown on the HID.  The whole HID layout can be Vertical or Horizontal. The number of levels shown when first rendered (rather than dynamic click and expand) can be controlled. Whether an item is shown more than once if it has multiple cross references and general layout parameters. These are further detailed in How to Set Hierarchy Diagram Properties. Once you are happy with the layout it can be saved for use next time you need a similar pattern.

The HID properties dialog
HID Properties Dialog

Your data may produce a short wide tree or a long narrow tree. This can be difficult to see on the screen. This video shows how changing the pivot point, (the node at which the orientation changes from listing horizontally to vertically) can alter the overall display to be more usable.

Requirements Management for Windows and Doors?

Requirements Management Isn’t Just For The Big Players.

Your boss says “Don’t be ridiculous you don’t need, requirements management for windows and doors!”…

Your client has asked that the new Town-Lodge is fitted with UPVC doors, windows and fascias throughout. All fire regulations for a medium occupancy building must be adhered to. Locks must have master key and single key access. Glass must meet the company’s privacy specification.  And so on….. Whether you are building a spacecraft with millions of parts with hundreds of engineers, or you’re a firm of three fitters running a building service, you have requirements to manage. The HID (Hierarchy Diagram below) shows that a large number of interdependencies, even for the supply of simple items, quickly builds. Consequently the complexity of managing those requirements becomes more of a task. The requirements for windows and doors to a 20 room Town-Lodge involves glass specifications and safety constraints. These may differ depending on the location and size of the window/door. Planning, using a tool can simplify the traceability of any job.

HID showing how complex even a requirement for a few windows and doors can be complex
Even Windows and Doors Can Benefit from Requirements Management

Managing Change

The quotation has been accepted by the Town-Lodge. However, you were careful enough to note that the price was ‘subject to regulatory change’. When Ref 125-ere-2008 comes up for review and an amendment is raised, it is easy to trace what this impacts. Running a query on the Safety Regulations and showing the linked items, furthermore,  it can be seen these refer to the Emergency Access Windows. The trace shows these are linked to Customer Requirement CR6 and CR8. Finally it is a simple case of writing the email to the Town-Lodge and explaining regulatory change requires thicker glass and this will change the price for these two windows. Then await their approval. Therefore, in answer to your boss, “I can see the future for a tool to give us requirements management for windows and doors – can we buy a copy of Cradle ?”

Running a query to find the impact of a change, requirements management for windows and doors is necessary
Finding the Impact of a Change

Validation and Acceptance

The Lodge has agreed that they will pay when the work has been completed satisfactorily. Prior to starting work you have agreed a set of acceptance criteria. There could be endless tweaks or subjective “I don’t think that’s finished” conversations unless clear acceptance criteria and associated validation techniques have been agreed. Imagine you have a noise reduction requirement, “The noise reduction between the window open and window closed shall be 6dB”. Record the pre-agreed acceptance method as a Cradle item, and link this to each of the requirements with noise acceptance criteria. (This requirement in turn is linked to the rooms that it affects)

  • Noise Reduction Measurement. A white noise generator shall be sited at 1m from the window. The position will be adjusted until a measurement of 80db or more is detected inside the room with the window open at a distance of 1m inside the room. A second reading shall be taken with the window shut and this shall be subtracted from the first reading.

Running a query against the noise test will find all the rooms that this applies to. Now you can make your measurements and record your findings. You now have full traceability for each aspect of the product being delivered to The Lodge. “Dear Boss, Submit the invoice, Cradle aided demonstration to The Lodge site manager that all our acceptance criteria had been met. I think we’ve proved a use for requirements management for windows and doors.”

Make a Hierarchy Diagram (HID)

What is a Hierarchy Diagram (HID)?

A Hierarchy Diagram (HID) is a diagram style that is used to graphically show cross references between items. A HID is a tree that starts with the item of interest (source item) and shows the items that are linked to it by cross references. Each of these items’ cross references can be shown with their cross referenced items.

What’s linked to what?

Generate a HID (Hierarchy Diagram) in Cradle for a clear graphical representation of how your items interconnect. Simple to see what depends on what at many levels.


Hierarchy Diagram Options and Information

When a HID is opened, the Control sidebar is refreshed to show the following tabs:

  • Starmap – Is a highly zoomed view of the diagram.
  • From Item – Shows details of the from item.
From Item
From Item
  • Hierarchy – Ability to define a hierarchy and set the links to follow for each item type.
  • Diagram Summary Information – Shows the number of items, cross references, levels and symbols in the current HID.
Diagram Summary
Diagram Summary

If you would like more information on Hierarchy Diagrams and how you can use them, you may find this Cradle help article useful.

Article Updtaed29/01/2019 –  Added more information and examples

Show Link Types in HIDs with Colour

Looking for a way to brighten up your day?!

What better way than using Hierachy Diagrams (HIDs) that show link types in colour!

Hierarchy Diagrams (HIDs) are an excellent way to show the relationships between items in your database. The boxes in the diagrams are the items and their connecting lines are the cross references.

You can define a colour for each cross reference link type in the schema. If you do, then these colours are used to draw the cross references in HIDs.

This means that you can easily interpret the connections shown by the HID as, for example ‘has child’ or ‘is satisfied by’, or ‘allocated to’ relationships.

If you have not tried setting colours for your cross reference link types, please try it and see how this will transform the ease with which your HIDs can be interpreted!

Screenshot showing Example Hierarchy Diagram
Example Hierarchy Diagram

Force Directed Graphs

We are curious to know what people think of using force directed graphs as a way to display the relationships between items in Hierarchy Diagrams (HIDs).

At the moment, HIDs are drawn using a fixed algorithm, in which you can control:

  • The orientation (vertical or horizontal)
  • If the HID will pivot (change orientation) and if so, the level at which it pivots.

Force directed graphs are an alternative way to arrange the same boxes (items) and lines (cross references) in a HID.

What do you think?