Perhitungan Tim untuk Inventory System

1. Estimasi Effort per Modul

ModulNamaComplexityMan-daysKeterangan
CorePlatformHigh40Auth, Multi-tenant, API Gateway
AMaster DataMedium25CRUD + Validasi
BStock ManagementHigh35Core logic, Stock card
CReceiving (GRN)Medium20Form + Workflow
DIssuing (GIN)Medium20Form + Workflow
ETransferMedium15Inter-warehouse
FPurchase OrderHigh30Approval + Vendor
GPurchase RequisitionMedium20PR Workflow
HReporting BasicMedium20Standard reports
IBarcode/QRMedium15Label + Scanner
JBatch/Lot TrackingMedium20FIFO/FEFO logic
KSerial NumberLow10Extension of J
LMin/Max & ReorderMedium15Auto calculation
MBOMHigh25Product structure
NProduction IntegrationHigh35WIP + Consumption
OQuality ControlMedium20QC Parameters
PDelivery/ShippingMedium20DO + Tracking
QReturn ManagementMedium15Return flow
RReporting AdvancedHigh25Report builder
SDashboard & AnalyticsHigh30KPI + Charts
TMobile AppHigh45Separate app
UIntegration APIHigh30External integrations
VMulti-locationMedium20Branch management
WApproval WorkflowMedium20Workflow engine
XNotificationLow10Email, WA, Push
YAudit TrailLow10Activity logging
ZAsset ManagementMedium25Asset + Depreciation
AAE-Commerce (B2B/B2C)High105Storefront, Payment, Shipping
TOTAL720Includes E-Commerce in all packages

2. Perhitungan Tim Berdasarkan Durasi

Asumsi Dasar

  • 1 bulan = 20 hari kerja
  • Produktivitas efektif = 80% (meeting, review, debugging)
  • Buffer untuk testing & bug fixing = 20%

Total Effort dengan Buffer

Base effort:     720 man-days (termasuk E-Commerce AA)
Testing buffer:  144 man-days (20%)
─────────────────────────────
Total:           864 man-days

Skenario A: 12 Bulan (Aggressive)

MetricValue
Total hari kerja240 hari
Effort dibutuhkan768 man-days
Developer dibutuhkan768 / (240 x 0.8) = 4 developers

Komposisi Tim (Senior-Heavy)

RoleJumlahLevelStatusMonthly Rate
Tech Lead1SeniorInternalRp 35.000.000
Backend Developer2Senior1 Internal + 1 FreelanceRp 28.000.000
Frontend Developer1SeniorInternalRp 28.000.000
Mobile Developer1MidFreelance (Phase 7)Rp 22.000.000
QA Engineer1MidInternalRp 18.000.000
UI/UX Designer1MidFreelanceRp 20.000.000
Project Manager1SeniorInternalRp 30.000.000
DevOps0.5MidFreelance (part-time)Rp 12.000.000

Total Tim Inti: 7-8 orang

Cost TypeMonthly12 Months
Internal (5 orang)Rp 139.000.000Rp 1.668.000.000
Freelance (3 orang)Rp 54.000.000Rp 648.000.000
TotalRp 193.000.000Rp 2.316.000.000

Skenario B: 18 Bulan (Normal)

MetricValue
Total hari kerja360 hari
Effort dibutuhkan768 man-days
Developer dibutuhkan768 / (360 x 0.8) = 2.7 ~ 3 developers

Komposisi Tim (Senior-Heavy)

RoleJumlahLevelStatusMonthly Rate
Tech Lead1SeniorInternalRp 35.000.000
Full-stack Developer2Senior1 Internal + 1 FreelanceRp 30.000.000
Mobile Developer1MidFreelance (Phase 7 only, 3 bln)Rp 22.000.000
QA Engineer1MidInternalRp 18.000.000
UI/UX Designer0.5MidFreelance (part-time)Rp 10.000.000
Project Manager0.5SeniorInternal (shared)Rp 15.000.000
DevOps0.5MidFreelance (part-time)Rp 12.000.000

Total Tim Inti: 5-6 orang

Cost TypeMonthly18 Months
Internal (4 orang)Rp 98.000.000Rp 1.764.000.000
Freelance (2.5 orang)Rp 52.000.000Rp 936.000.000
Mobile (3 bulan)Rp 22.000.000Rp 66.000.000
TotalRp 150.000.000Rp 2.766.000.000

Skenario C: 24 Bulan (Relaxed)

MetricValue
Total hari kerja480 hari
Effort dibutuhkan768 man-days
Developer dibutuhkan768 / (480 x 0.8) = 2 developers

Komposisi Tim (Senior-Heavy)

RoleJumlahLevelStatusMonthly Rate
Tech Lead/Architect1SeniorInternalRp 35.000.000
Full-stack Developer1SeniorInternalRp 30.000.000
Mobile Developer1MidFreelance (Phase 7 only, 3 bln)Rp 22.000.000
QA Engineer0.5MidFreelance (part-time)Rp 9.000.000
UI/UX Designer0.5MidFreelance (part-time)Rp 10.000.000
DevOps0.25MidFreelance (minimal)Rp 6.000.000

Total Tim Inti: 3-4 orang

Cost TypeMonthly24 Months
Internal (2 orang)Rp 65.000.000Rp 1.560.000.000
Freelance (1.25 orang)Rp 25.000.000Rp 600.000.000
Mobile (3 bulan)Rp 22.000.000Rp 66.000.000
TotalRp 90.000.000Rp 2.226.000.000

3. Perbandingan Semua Skenario

Senior-Heavy Team

SkenarioDurasiTimMonthly CostTotal Cost
A12 bulan7-8 orangRp 193.000.000Rp 2.316.000.000
B18 bulan5-6 orangRp 150.000.000Rp 2.766.000.000
C24 bulan3-4 orangRp 90.000.000Rp 2.226.000.000

Balanced Mix Team

SkenarioDurasiTimMonthly CostTotal Cost
A12 bulan9-10 orangRp 211.000.000Rp 2.532.000.000
B18 bulan6-7 orangRp 127.000.000Rp 2.352.000.000
C24 bulan4-5 orangRp 86.000.000Rp 2.130.000.000

4. Rekomendasi

Best Value

Skenario C + Balanced Mix

  • Durasi: 24 bulan
  • Tim: 4-5 orang
  • Total Cost: Rp 2.130.000.000

Pros: Biaya terendah, waktu untuk quality

Cons: Time to market lama

Best Speed

Skenario A + Senior-Heavy

  • Durasi: 12 bulan
  • Tim: 7-8 orang
  • Total Cost: Rp 2.316.000.000

Pros: Delivery cepat, kualitas tinggi

Cons: Biaya tinggi, risiko burnout

Best Balance

Skenario B + Balanced Mix

  • Durasi: 18 bulan
  • Tim: 6-7 orang
  • Total Cost: Rp 2.352.000.000

Pros: Keseimbangan speed & cost

Cons: Butuh mentoring untuk junior

5. Timeline per Phase dengan Resource Allocation

Skenario B (18 bulan) - Balanced Mix

gantt title Timeline Skenario B - 18 Bulan dateFormat YYYY-MM section Foundation Phase 1 Foundation :p1, 2025-01, 3M section Operations Phase 2 Operations :p2, after p1, 3M section Procurement Phase 3 Procurement :p3, after p2, 3M section Advanced Phase 4 Advanced :p4, after p3, 3M section Distribution Phase 5 Distribution :p5, after p4, 2M section Intelligence Phase 6 Intelligence :p6, after p5, 2M section Extensions Phase 7 Extensions :p7, after p6, 2M
PhaseDurasiFocus TeamSupport
Phase 1: FoundationBulan 1-3Tech Lead + 2 DevUI/UX
Phase 2: OperationsBulan 4-62 Dev + QATech Lead review
Phase 3: ProcurementBulan 7-92 Dev + QAUI/UX
Phase 4: AdvancedBulan 10-122 Dev + QADevOps
Phase 5: DistributionBulan 13-142 Dev + QA-
Phase 6: IntelligenceBulan 15-162 Dev + QAUI/UX
Phase 7: ExtensionsBulan 17-18Mobile Dev + 1 DevQA

6. Additional Costs (Estimasi)

ItemOne-timeMonthly
Cloud Infrastructure-Rp 5.000.000 - 15.000.000
Development ToolsRp 10.000.000Rp 2.000.000
Third-party Services-Rp 3.000.000
Training & CertificationRp 20.000.000-
Contingency (10%)-+10% of total