Kaung Myat Tun

🔧 1. Mandatory Dependency

Also called: Hard logic

📌 Definition:

Dependencies that are legally or physically required, based on the nature of the work or contractual obligations.

✅ Characteristics:

• Cannot be modified without violating physical laws, legal regulations, or required process flows.
• Often non-negotiable.

📍 Example:

• You cannot test a product before it is built.
• Concrete must cure before framing can begin.

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🧭 2. Discretionary Dependency

Also called: Soft logic, preferred logic, or preferential logic

📌 Definition:

Dependencies established by the project team based on best practices, preferences, or process decisions.

✅ Characteristics:

• Can be modified if needed (e.g., during fast-tracking or re-sequencing).
• Based on team judgment, not physical constraints.

📍 Example:

• You prefer to complete all documentation before starting training, but it’s not mandatory — they could happen in parallel.

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🌍 3. External Dependency

📌 Definition:

Dependencies that involve relationships between project activities and non-project activities (i.e., outside your control).

✅ Characteristics:

• Often outside the project team’s influence.
• Typically non-modifiable.

📍 Example:

• Waiting for government approval before launching.
• A vendor must deliver hardware before installation begins.

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🏢 4. Internal Dependency

📌 Definition:

Dependencies within the control of the project team or organization.

✅ Characteristics:

• May be modifiable, unless tied to regulatory, safety, or policy constraints.
• Can often be adjusted to optimize the schedule.

📍 Example:

• Development cannot begin until internal design approval is given.
• One team’s task depends on another internal team’s deliverable.

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🧠 Summary Table

Type	Modifiable?	Controlled By	Example
Mandatory	❌ No	Nature/Laws/Contracts	Concrete must cure before framing
Discretionary	✅ Yes	Project Team	Finish docs before starting training
External	❌ No	Outside parties	Government approval needed before launch
Internal	⚠️ Sometimes	Project Organization	Dev waits for internal design approval

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🛠 In Schedule Compression:

• Fast-tracking is only possible with discretionary or sometimes internal dependencies.
• Mandatory and external dependencies are usually fixed and cannot be compressed.