# Standard and custom objects, relationships and record types

*Platform User Experience Designer Study Guide · Declarative Design · Last updated October 16, 2026 · https://www.certifyforce.com/study-guide/user-experience-designer/declarative-design/standard-and-custom-objects-relationships-and-record-types*

How a designer's data-model choices shape what users see and type: standard objects before custom ones, lookup vs master-detail vs hierarchical vs junction, roll-up summaries and cross-object formulas, Contacts to Multiple Accounts, and record types with their page layout assignment.

- Certification: Salesforce Platform User Experience Designer
- Exam section: Declarative Design
- Study guide: https://www.certifyforce.com/study-guide/user-experience-designer

**Official exam objective:**

> Given a scenario, describe how core Salesforce objects function, how that can affect end-user experience, and when to use and customize them.

## What the exam expects

- Decide when a standard object (Lead, Case, Activities) fits and when a custom object with a tab is justified.
- Choose lookup, master-detail, hierarchical or a junction object from what users must see, what happens on delete and who can access child records.
- Reduce data entry with roll-up summary fields (master side) and cross-object formulas (child side).
- Explain the user impact of Contacts to Multiple Accounts and of record types, including layout assignment by record type and profile.

Key terms: **master-detail** (tight parent-child link where the master controls deletion, ownership and sharing of the detail); **junction object** (custom object that is the detail in two master-detail relationships, modelling many-to-many); **roll-up summary field** (master-side field that counts or sums detail records); **cross-object formula** (formula that reads fields on a related parent record); **record type** (a variant of an object with its own business process, picklist values and page layouts).

## Key facts

| Fact | Detail | Source |
|---|---|---|
| Relationship field location | Always on the detail (child) object | [Create Object Relationships](https://trailhead.salesforce.com/content/learn/modules/data_modeling/object_relationships) |
| Lookup default on parent delete | Clear the value of this field | [Object Relationships Overview](https://help.salesforce.com/s/articleView?id=platform.overview_of_custom_object_relationships.htm&type=5) |
| Master-detail limit | Up to 2 per custom object | [Considerations for Object Relationships](https://help.salesforce.com/s/articleView?id=platform.relationships_considerations.htm&type=5) |
| Detail record owner | Not available; set to the master's owner | [Object Relationships Overview](https://help.salesforce.com/s/articleView?id=platform.overview_of_custom_object_relationships.htm&type=5) |
| Lookup to master-detail conversion | Only if every record has a lookup value | [Considerations for Object Relationships](https://help.salesforce.com/s/articleView?id=platform.relationships_considerations.htm&type=5) |
| Roll-up summary types | COUNT, SUM, MIN, MAX on the master | [Roll-Up Summary Field](https://help.salesforce.com/s/articleView?language=en_US&id=platform.fields_about_roll_up_summary_fields.htm&type=5) |
| Cross-object formula reach | Up to 10 relationships; not in default values | [What Is a Cross-Object Formula?](https://help.salesforce.com/s/articleView?id=platform.customize_cross_object.htm&type=5) |
| Log a Call result | Saved as a completed task | [Quick Actions](https://help.salesforce.com/s/articleView?id=platform.actions_overview.htm&type=5) |
| Indirect contacts in reports | Not in Account & Contact report type | [Considerations for Relating a Contact to Multiple Accounts](https://help.salesforce.com/s/articleView?id=sales.shared_contacts_considerations.htm&type=5) |
| Record type layout assignment | One layout for all profiles or one per profile | [Create Record Types](https://help.salesforce.com/s/articleView?language=en_US&id=platform.creating_record_types.htm&type=5) |

## Check yourself

- Why does a Hikes related list appear on the Trail page when the lookup is on Hike?
- When must a custom relationship to User be hierarchical rather than a lookup?
- Why can't a roll-up summary total invoices related to Account by a lookup?
- What decides which page layout a user sees for a record type?

## Sources

- [Object Relationships Overview](https://help.salesforce.com/s/articleView?id=platform.overview_of_custom_object_relationships.htm&type=5)
- [Considerations for Object Relationships](https://help.salesforce.com/s/articleView?id=platform.relationships_considerations.htm&type=5)
- [Roll-Up Summary Field](https://help.salesforce.com/s/articleView?language=en_US&id=platform.fields_about_roll_up_summary_fields.htm&type=5)
- [What Is a Cross-Object Formula?](https://help.salesforce.com/s/articleView?id=platform.customize_cross_object.htm&type=5)
- [Formula Field Limits and Restrictions](https://help.salesforce.com/s/articleView?id=platform.formula_field_limits.htm&type=5)
- [Tailor Business Processes to Different Record Types Users](https://help.salesforce.com/s/articleView?id=platform.customize_recordtype.htm&type=5)
- [Create Record Types](https://help.salesforce.com/s/articleView?language=en_US&id=platform.creating_record_types.htm&type=5)
- [Contacts to Multiple Accounts](https://help.salesforce.com/s/articleView?id=sales.shared_contacts_overview.htm&type=5)
- [Considerations for Relating a Contact to Multiple Accounts](https://help.salesforce.com/s/articleView?id=sales.shared_contacts_considerations.htm&type=5)
- [Convert Qualified Leads](https://help.salesforce.com/s/articleView?id=sales.leads_convert.htm&language=en_US&type=5)
- [Assign Cases](https://help.salesforce.com/s/articleView?id=cases_assign.htm&language=en_US&type=5)
- [Quick Actions](https://help.salesforce.com/s/articleView?id=platform.actions_overview.htm&type=5)
- [Optimize Customer Data with Standard and Custom Objects](https://trailhead.salesforce.com/content/learn/modules/data_modeling/objects_intro)
- [Create Object Relationships](https://trailhead.salesforce.com/content/learn/modules/data_modeling/object_relationships)
- [Explore the New Sales Tools](https://trailhead.salesforce.com/content/learn/modules/lex_migration_whatsnew/lex_migration_whatsnew_crm)

## About the full unit

The "Core concepts", "Exam traps" and "Worked scenario" sections of this unit, its 13 linked practice questions, and unlimited timed mock exams are included with the Platform User Experience Designer pack (USD $19): https://www.certifyforce.com/practice-exams