April 2018 - 3SL Blog

30th April 20182nd May 2018

Creating Link Rules in Cradle

Creating link rules in Cradle is performed in the Link Rules section of Project Setup. If you require more information on how to find this please see the previous post Getting Started with Link Rules in Cradle.

New link rules are added by selecting the Add… button to the right of the Project Setup window.

Select the Add... button to create link rules — Select the Add… button to create new link rules

Selecting Add… opens the Link Rule Setup dialog. The purpose of this window is to select the attributes for our new link rule.

Creating link rules in the Link Rule Setup dialog. — Cradle’s Link Rule Setup Dialog

Specifying Options and Attributes in Link Rule Setup

When creating link rules, you need to decide their purpose and to what items/aspects you want them to apply.

Rule Control

Firstly decide whether the rule is enabled (this allows rules to be written but whether they are applied or not may depend on the stage the current project is at)
Next decide whether this rule is an ALLOW (Permit the operation) or PREVENT (Prevent operation) action.
Choose whether this is a blanket rule, or whether it only applies to certain Users, or User Teams.

Cross Reference Attributes

Pick the item types that this refers to. (If these are model-based there are further options to fill)
Optionally restrict this to items with a particular ID. (This might be useful if you have an over arching item e.g. “Reference Set External” to which all external references are linked with a special INCLUDES link type which can be made by anyone adding a reference)
The link type can be specified as any of those defined for the project, or <any> which allows all link types to match, or a Link Group which is a set of link types.
Choose the cardinality allowed.
Optionally mark this as the default link type between two specific item types. This will then be the link type chosen when creating cross references between items of the specified type, either to set the UI as default or when no UI option is available for the action.

Matched Rule Controls

This defines what the rule will allow in terms of Creation, Deletion or Modification.

Ordering Rules

When creating link rules, remember they are applied in a top down fashion, the first match wins. If there is a narrow case you don’t want to allow, you may choose to PREVENT this first and then add an ALLOW below it. If there is a narrow case you want to ALLOW you would order this first and then PREVENT everything else.

Example:

To allow Requirements to be linked to any Equipment Design item, with any link except CHILD you would define two rules.

PREVENT Requirement ⎯ CHILD → EQUIPMENT DESIGN
ALLOW Requirement ⎯ <any> → EQUIPMENT DESIGN

To allow the Requirements to be linked to other Requirements using the CHILD link, and nothing else a further two rules would be added.

ALLOW Requirement ⎯ CHILD → Requirement
PREVENT Requirement ⎯ <any>→ Requirement

How the order of link rules plays an important part in their definition — Link Rule Ordering

18th April 201814th March 2023

World Amateur Radio Day 2018

World Amateur Radio Day 18th April 2018

Celebrating world amateur radio day, we look at the way pre internet, radio shrunk the world. Using a variety of frequencies to transmit locally, or over long distances, radio ‘hams’ passed messages round the world long before there was Twitter, SMS or even phone calls. Relays passed on messages acting as go-betweens in the same way our major backbone carriers pass our messages today. However, it was all a little more civilised and ‘human’ rather than a hub of computers and machine readable protocol.

An "sd" representing an intial amateur radio ham contact — Ham Sequence Diagram

So “CQ from 3SL, calling CQ three sierra lima and listening” “Hello all on World Amateur Radio Day 2018! ” To find out more about your local radio society, head over to your countries associations. International Amateur Radio Union Radio Society of Great Britain and local to us here in Cumbria Furness Amateur Radio Society

16th April 201823rd August 2022

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.

12th April 20187th October 2022

April 2018 Newsletter

Happy New Year!?

Yes, I know it’s the April 2018 Newsletter. The Gregorian calendar was introduced in 1582. The switch by countries was gradual, with the UK changing in 1752. During the switch the UK lost 11 days in September, and the start of the year was moved to January the 1st. We covered some of the strange naming conventions in our October newsletter. Originally the first day of a ‘new year’ was 25th March, this sudden jump would have messed up financial institutions accounts. So they kept the start of the fiscal year more or less where it was, shifting by those same 11 days to 5th April. Or it could have been that the accountants were so drunk at Christmas they just couldn’t face doing the accounts when they returned to work. Take your pick.

So if you are lucky enough to be dealing with a new budget for the “new year” now’s the time to check you are getting value for money across all your projects. Are you still dealing with several different tools to manage your Requirements and model your Systems?
Could you consolidate these tools and methods by adding extra licences to your Cradle installation and then on-boarding ^{(yuck -Sorry read that one in a trendy blog post somewhere)} the less enlightened?
On the other hand if you’ve been Spring cleaning and found your project a little out of kilter, you may realise that the management view you have over it, is not as clear as it ought to be. Then maybe adding a Dash or Metric licence to Cradle could help with getting to grips on the health of your project. However we can help, don’t hesitate to call us here in the UK or your local distributor.

Metrics

Measurements and collation of the results are an important management tool.

It is obviously important to manage and track the right thing. Using the ludicrous quote “The majority of people involved in accidents were wearing white underwear….”, you may jump to the conclusion that brightly coloured pants will keep you safe. Of course this statement is completely meaningless without context because if white pants are the most popular colour you could make that statement apply to any topic.

Provided you are measuring sensible information, percentage of Requirements that are Accepted, or Underway gives a really useful view about the maturity of your project.

In Cradle you can define any number of metrics, save and re-run them at a later date. A metric is made up of a set of elements, each element is a query to the database to retrieve item(s), and an analysis operation on these items. This could be a simple count, or a more comprehensive coverage analysis of attributes. Available functions include:

Item count
Minimum value, Maximum value
Averages/spread (mean, median, mode(s), variance (population-based), range, standard deviation (population-based) and semi-interquartile range)
Total / Weighted total of values
Range of values
Pivot table for category values
Coverage statistics

The returned values can also be further manipulated with Metric calculations, combining values with basic mathematical operations. Delve into the help section for more information or read the flyer.

Cradle Features Coming Soon….

As we mentioned in February Cradle 7.4 is on the way. Look out for; New colouring options in (HID) Hierarchy Diagrams, Additional Regex (regular expression) matches in queries, Unique attribute checks……..

Twitter

Yey! Our followers still steadily climbing, but will you be the one that pushes us over the 400 mark?? What happens when we get to 404, do we get Follower Not Found? ^{(Oh dear, sorry, bad engineering joke crept in. Ed.)}

We read how conventionally CO is seen as bad, but there could be a route to making fuel.

We gave you a peek inside 3SL towers at some of the great staff we have.

We found ourselves hungry on St. Patrick’s day.

And took comfort that we were missed…..

Hints of the Month

Last month’s blog articles included:

We highlighted types of storage in Cradle, last month. Think of this too as a way to get tighter control over some of those files that form part of your Requirements set. Adding them to a Cradle item and then adding meta data to describe how they fit into your project.

We also looked at setting your model drawing preferences.

And to fit in with our Spring Cleaning, some housekeeping tips in Cradle.

You can read Hints & Tips in the 3SL Blog