What Is the T&M Model of S4 Consulting?

Author: Nu Huynh – Consulting Director

The Time & Materials (T&M) model is a pricing approach where ERP clients pay only for verified consulting and development hours actually delivered.
At S4 Consulting, every billable hour is recorded, reviewed, approved, and invoiced directly from Acumatica Cloud ERP, enabling real-time visibility into cost, progress, and delivered value.

Why Is the T&M Model Widely Used in Developed Markets?

T&M is commonly adopted in mature economies where transparency and accountability are fundamental business principles.
Every task must be measurable, every hour must justify its value, and every cost must be traceable to an actual outcome.

In Vietnam, S4 Consulting is among the early ERP service providers applying T&M consistently, based on a delivery philosophy that prioritizes real operational results over contractual assumptions. This approach allows Vietnamese enterprises to work with international-standard delivery practices, with full clarity on scope, effort, and responsibilities.

How Does the T&M Process Work at S4 Consulting?

The process follows the U.S. Professional Services delivery model and is fully governed inside Acumatica Cloud ERP.

The 5-Step T&M Fee Model

1. Scope Estimation and Pre-Approval

S4 breaks down the scope into granular work items, each with estimated hours and complexity levels.
Clients review and approve the scope before execution begins.

2. Execution and Time Capture

Consultants and Developers perform assigned tasks.
All working hours are logged directly into the ERP system with task-level descriptions and are permanently stored.

3. Weekly Timesheet Reconciliation

Every week, S4 provides a reconciliation report including:

• total hours consumed
• daily breakdown
• assigned role and task
• status: Submitted / Approved

This allows clients to see real progress, not assumptions, and adjust priorities early.

4. Provisional Invoice at the Start of the Following Month

A provisional invoice is issued based on all billable hours of the previous month. This serves as a cost snapshot before final confirmation.

5. Official Invoice After Client Confirmation

Once confirmed, the official invoice is issued. All invoice figures match 100% with approved timesheets and weekly reports in the ERP system.

Why T&M Often Costs Less Than Fixed-Fee ERP Contracts

Based on internal delivery data at S4 Consulting, approximately 65% of our ongoing ERP engagements are currently delivered under the T&M model.
Across these projects, clients spend around 40% less compared to traditional fixed-fee contracts, while maintaining the same delivery scope and quality.

This cost difference exists because fixed-fee contracts typically embed risk buffers to protect against uncertainty. T&M removes those hidden buffers and replaces them with weekly transparency and continuous scope control.

In real ERP projects in Vietnam, weekly timesheet reviews often reveal low-value or unnecessary work early, allowing both sides to stop or re-prioritize before costs accumulate. This level of control is rarely achievable in fixed-fee models, where issues are usually discovered too late.

Source: Internal delivery statistics of S4 Consulting.

Absolute Transparency Enabled by Acumatica Cloud ERP

All T&M data at S4 Consulting is managed and exported directly from Acumatica Professional Services ERP.
Clients can verify at any time:

• who performed the work
• when the work was done
• which task it belongs to
• billable time per task
• approval history
• immutable timesheet records after approval

This creates hour-level clarity, not just invoice-level summaries.

Which Companies in Vietnam Benefit Most from the T&M Model?

The T&M model is particularly suitable for enterprises that:

• want to optimize ERP implementation and support costs for Oracle NetSuite or Acumatica
• require a second ERP service provider to support or stabilize an existing system without committing to fixed monthly costs

Why Choose S4 Consulting for T&M-Based ERP Services?

S4 Consulting is a Gold Partner of Acumatica in Vietnam and provides Oracle NetSuite implementation consulting services.
By working with S4 under the T&M model, enterprises gain:

• internationally standardized and auditable delivery processes
• full visibility into every billable hour
• experienced consultants who understand ERP operations in Vietnam
• optimized cost structures through the Fast & Saving delivery approach

Every working hour is measurable and contributes directly to a real-time financial management system.

FAQ

Does the T&M model carry a risk of cost overruns?

Yes, if requirements change frequently without control. However, weekly reporting and pre-approved scope estimates allow CEOs to monitor and adjust costs clearly at each phase.

Can clients access full timesheet records?

Yes. All timesheets are stored in Acumatica with task descriptions and approval history.

Are invoices fully transparent?

Invoices are generated directly from approved timesheets. Each invoice line is traceable to the individual and the task performed.

Are weekly reports mandatory?

Yes. Weekly reporting is a mandatory requirement in S4’s T&M delivery model to maintain transparency and scope control.

What if the project needs to be audited?

All timesheet data and approval logs can be audited at any time.