Kualitas Perangkat Lunak — Untung Yuhana (ITS)

🛡️ Kualitas Perangkat Lunak — Proses, Standar & Jaminan Mutu

Buku: Kualitas Perangkat Lunak — Prof. Dr. Ir. Untung Yuhana, ITS
Fokus: SQA, model kualitas, V&V, metric, CMMI, SQAP, audit
Praktik: checklist + template — gak perlu tool mahal

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1. Fondasi Kualitas PL

SQA vs QC vs Testing:

• SQA (Software Quality Assurance) — proses, sistemik, preventif
• QC (Quality Control) — produk, detektif
• Testing — kegiatan teknis verifikasi

Cost of Quality:

              ┌── Prevention (training, review, standar)
              │
Biaya Kualitas ── Appraisal (testing, audit, inspeksi)
              │
              ├── Internal Failure (bug sebelum rilis)
              │
              └── External Failure (bug setelah rilis — paling mahal!)

5 Dimensi Proyek PL:

Dimensi	Arti
Ruang lingkup	Fitur apa aja
Waktu	Deadline
Biaya	Budget
Kualitas	Standar
Risiko	Hal yang bisa salah

Kultur Kualitas:

• Kualitas bukan tanggung jawab QA doang
• Kualitas dibangun dari awal, bukan diperiksa di akhir
• Dokumentasi itu alat, bukan beban

Contoh implementasi kultur kualitas dalam proyek:

# Dokumentasi kode
def calculate_total(price, quantity):
    """
    Menghitung total harga.
 
    Args:
        price (float): Harga satuan
        quantity (int): Jumlah item
 
    Returns:
        float: Total harga
    """
    return price * quantity
 
# Tes unit untuk kode di atas
import unittest
 
class TestCalculateTotal(unittest.TestCase):
    def test_calculate_total(self):
        price = 100.0
        quantity = 2
        total = calculate_total(price, quantity)
        self.assertEqual(total, 200.0)
 
if __name__ == '__main__':
    unittest.main()

---

2. Model Kualitas

Model	Tahun	Fokus	Cocok untuk
McCall	1977	3 perspektif: operation, revision, transition	Legacy system
Boehm	1978	As-is utility + maintainability + portability	Proyek praktis
FURPS	1987	Func, Usability, Reliability, Perf, Support	Produk komersial
Ghezzi	1991	Formal: sintaks, semantik, pragmatik	Penelitian
Dromey	1995	Product-based quality	Kompleks
SATC	1996	NASA mission-critical	Safety-critical

Paling berguna buat praktik: FURPS — sederhana, langsung relate ke fitur.

Contoh evaluasi POS dengan FURPS:

Faktor	Evaluasi
Functionality	Bisa transaksi + cetak nota? ✅
Usability	Kasir paham tanpa training? ⚠️ perlu UX
Reliability	Kalau listrik mati? data aman? ✅ offline-first
Performance	Loading < 2 detik? 🤷
Supportability	Kalau error gampang debug? ✅ code terstruktur

Contoh implementasi FURPS dalam kode:

# Functionality: transaksi
def process_transaction(item, quantity):
    # ...
    return transaction_id
 
# Usability: UX sederhana
def display_transaction(transaction_id):
    # ...
    print("Transaksi berhasil!")
 
# Reliability: data aman
def save_transaction(transaction_id, data):
    # ...
    return True
 
# Performance: loading cepat
def get_transaction(transaction_id):
    # ...
    return transaction_data
 
# Supportability: debug mudah
def debug_transaction(transaction_id):
    # ...
    print("Error: transaksi gagal!")

---

3. Verifikasi & Validasi (V&V)

Perbedaan:

• Verifikasi: “Are we building the product right?” — proses, spec, standard
• Validasi: “Are we building the right product?” — kebutuhan user, domain

Teknik V&V:

Teknik	Apa	Siapa
Review	Baca dokumen/requirement	Tim + stakeholder
Inspection	Formal, checklist	Peer + moderator
Walkthrough	Presentasi penulis	Tim
Testing	Eksekusi sistem	Tester

Traceability Matrix: Forward (requirement → test) + Backward (test → requirement)

Req ID | Spesifikasi        | Test ID | Hasil
───────┼────────────────────┼─────────┼───────
F-001  | Input transaksi   | T-001   | ✅
F-002  | Cetak nota        | T-002   | ✅
F-003  | Hitung total      | T-003   | ⚠️ rounding error

Contoh implementasi V&V dalam kode:

# Verifikasi: proses
def verify_process(transaction_id):
    # ...
    return True
 
# Validasi: produk
def validate_product(transaction_id):
    # ...
    return True
 
# Tes unit untuk verifikasi dan validasi
import unittest
 
class TestVerifyAndValidate(unittest.TestCase):
    def test_verify_process(self):
        transaction_id = 1
        self.assertTrue(verify_process(transaction_id))
 
    def test_validate_product(self):
        transaction_id = 1
        self.assertTrue(validate_product(transaction_id))
 
if __name__ == '__main__':
    unittest.main()

---

4. Review

3 Level Review:

1. Requirement Review — completeness, consistency, testability
2. Design Review — arsitektur, pattern, coupling/cohesion
3. Code Review — bugs, style, security, performance

Code Review Checklist:

• Logic sesuai spec?
• Input validation?
• Error handling? (gak cuma try-catch kosong)
• No hardcoded secrets?
• Consistent naming?
• Fungsi pure kalau bisa?
• Test coverage untuk logic kritis?

Contoh implementasi code review dalam kode:

# Code review: logic
def calculate_total(price, quantity):
    # ...
    return price * quantity
 
# Code review: input validation
def validate_input(price, quantity):
    # ...
    return True
 
# Code review: error handling
def handle_error(error):
    # ...
    return error_message
 
# Tes unit untuk code review
import unittest
 
class TestCodeReview(unittest.TestCase):
    def test_calculate_total(self):
        price = 100.0
        quantity = 2
        total = calculate_total(price, quantity)
        self.assertEqual(total, 200.0)
 
    def test_validate_input(self):
        price = 100.0
        quantity = 2
        self.assertTrue(validate_input(price, quantity))
 
    def test_handle_error(self):
        error = "Error: invalid input"
        error_message = handle_error(error)
        self.assertEqual(error_message, "Error: invalid input")
 
if __name__ == '__main__':
    unittest.main()

---

5. Pengukuran (Metric & CMMI)

3 Jenis Metric:

Metric	Contoh
Product	LOC, cyclomatic complexity, bug density
Process	Lead time, defect removal efficiency
Project	Schedule variance, cost variance

CMMI Levels:

Level	Nama	Arti
1	Initial	Chaos, hero culture
2	Managed	Ada proses dasar, repeatable
3	Defined	Proses standar perusahaan
4	Quantitatively Managed	Diukur + dikontrol statistik
5	Optimizing	Continuous improvement

Target realistis untuk proyek kecil: Level 2 — proses documented + repeatable.

ISO 25023: Pengukuran kualitas sistem — turunan dari ISO 25010 (product quality model).

Contoh implementasi pengukuran dalam kode:

# Metric: LOC
def calculate_loc(code):
    # ...
    return loc
 
# Metric: cyclomatic complexity
def calculate_cc(code):
    # ...
    return cc
 
# Metric: bug density
def calculate_bd(code):
    # ...
    return bd
 
# Tes unit untuk metric
import unittest
 
class TestMetric(unittest.TestCase):
    def test_calculate_loc(self):
        code = "def calculate_total(price, quantity): return price * quantity"
        loc = calculate_loc(code)
        self.assertEqual(loc, 1)
 
    def test_calculate_cc(self):
        code = "def calculate_total(price, quantity): return price * quantity"
        cc = calculate_cc(code)
        self.assertEqual(cc, 1)
 
    def test_calculate_bd(self):
        code = "def calculate_total(price, quantity): return price * quantity"
        bd = calculate_bd(code)
        self.assertEqual(bd, 0)
 
if __name__ == '__main__':
    unittest.main()

---

6. Manajemen Risiko

Proses:

1. Identifikasi — brainstorming, checklist, assumption analysis
2. Analisis — Probability × Impact = Risk Exposure
3. Response — Avoid, Transfer, Mitigate, Accept
4. Monitoring — review tiap sprint

Contoh Risk Register:

Risiko	P	I	Skor	Response
Listrik mati	4	5	20	Mitigate → UPS
HDD rusak	2	5	10	Mitigate → backup harian
Cashier error	3	3	9	Avoid → validasi input
Tidak laku	3	4	12	Accept → MVP dulu

Contoh implementasi manajemen risiko dalam kode:

# Identifikasi risiko
def identify_risk(transaction_id):
    # ...
    return risk
 
# Analisis risiko
def analyze_risk(risk):
    # ...
    return risk_exposure
 
# Response risiko
def respond_risk(risk_exposure):
    # ...
    return response
 
# Tes unit untuk manajemen risiko
import unittest
 
class TestRiskManagement(unittest.TestCase):
    def test_identify_risk(self):
        transaction_id = 1
        risk = identify_risk(transaction_id)
        self.assertIsNotNone(risk)
 
    def test_analyze_risk(self):
        risk = "Listrik mati"
        risk_exposure = analyze_risk(risk)
        self_ASSERTIsNotNone(risk_exposure)
 
    def test_respond_risk(self):
        risk_exposure = 20
        response = respond_risk(risk_exposure)
        self_ASSERTIsNotNone(response)
 
if __name__ == '__main__':
    unittest.main()

---

7. SQAP (IEEE 730)

Komponen SQAP:

1. Purpose — why SQA needed
2. Reference — standar yang dipakai
3. Management — roles, responsibilities
4. Documentation — apa yang perlu didok
5. Standards — coding standard, naming
6. Review & Audit — jadwal
7. Testing — strategy
8. Problem Reporting — bug tracking
9. Tools — apa aja yang dipake

Contoh implementasi SQAP dalam kode:

# Purpose: SQA
def purpose_sqa():
    # ...
    return purpose
 
# Reference: standar
def reference_standard():
    # ...
    return standard
 
# Management: roles
def management_roles():
    # ...
    return roles
 
# Tes unit untuk SQAP
import unittest
 
class TestSQAP(unittest.TestCase):
    def test_purpose_sqa(self):
        purpose = purpose_sqa()
        self.assertIsNotNone(purpose)
 
    def test_reference_standard(self):
        standard = reference_standard()
        self_ASSERTIsNotNone(standard)
 
    def test_management_roles(self):
        roles = management_roles()
        self_ASSERTIsNotNone(roles)
 
if __name__ == '__main__':
    unittest.main()

---

8. Audit PL

Jenis Audit:

• Process Audit — “Apakah kita ikutin proses yang sudah ditetapkan?”
• Product Audit — “Apakah produk sesuai spec?”
• Supplier Audit — “Apakah vendor memenuhi standar?”

Gampangnya: Audit = checklist ± observasi ± wawancara.

Contoh implementasi audit dalam kode:

# Process audit
def process_audit(transaction_id):
    # ...
    return result
 
# Product audit
def product_audit(transaction_id):
    # ...
    return result
 
# Supplier audit
def supplier_audit(vendor_id):
    # ...
    return result
 
# Tes unit untuk audit
import unittest
 
class TestAudit(unittest.TestCase):
    def test_process_audit(self):
        transaction_id = 1
        result = process_audit(transaction_id)
        self_ASSERTIsNotNone(result)
 
    def test_product_audit(self):
        transaction_id = 1
        result = product_audit(transaction_id)
        self_ASSERTIsNotNone(result)
 
    def test_supplier_audit(self):
        vendor_id = 1
        result = supplier_audit(vendor_id)
        self_ASSERTIsNotNone(result)
 
if __name__ == '__main__':
    unittest.main()

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🔗 Koneksi ke Buku Lain

• V&V → validasi output NN (Book 1) — apa prediksi stok akal?
• SQAP → template book buat deployment Moodle (Book 3)
• Fuzzy → evaluasi subjektif usability pakai membership function (Book 1)
• Risk → risiko power outage di remote area (Book 3)

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✅ Ringkasan Praktik

Yang bisa diterapkan sekarang	Gak perlu
Traceability matrix (spreadsheet)	Tool mahal
Code review checklist	Jira Enterprise
Risk register (Google Sheets)	Consultant
SQAP template (markdown)	Sertifikasi ISO
CMMI Level 2 assessment	Assessment mahal

Kunci: All about process mindset — dokumentasi, review, ukur, improve. Bukan soal tool mewah.

Contoh implementasi ringkasan praktik dalam kode:

# Traceability matrix
def create_traceability_matrix():
    # ...
    return matrix
 
# Code review checklist
def create_code_review_checklist():
    # ...
    return checklist
 
# Risk register
def create_risk_register():
    # ...
    return register
 
# SQAP template
def create_sqap_template():
    # ...
    return template
 
# CMMI Level 2 assessment
def create_cmmi_level2_assessment():
    # ...
    return assessment
 
# Tes unit untuk ringkasan praktik
import unittest
 
class TestRingkasanPraktik(unittest.TestCase):
    def test_create_traceability_matrix(self):
        matrix = create_traceability_matrix()
        self_ASSERTIsNotNone(matrix)
 
    def test_create_code_review_checklist(self):
        checklist = create_code_review_checklist()
        self_ASSERTIsNotNone(checklist)
 
    def test_create_risk_register(self):
        register = create_risk_register()
        self_ASSERTIsNotNone(register)
 
    def test_create_sqap_template(self):
        template = create_sqap_template()
        self_ASSERTIsNotNone(template)
 
    def test_create_cmmi_level2_assessment(self):
        assessment = create_cmmi_level2_assessment()
        self_ASSERTIsNotNone(assessment)
 
if __name__ == '__main__':
    unittest.main()