Perancangan dan Pengendalian Product

Pola Trend

Data

Bulan	Periode (t)	Demand (Dt)
1	1	10
2	2	13
3	3	18
4	4	22
5	5	27
6	6	33
7	7	35
8	8	43
9	9	48
10	10	55
11	11	58
12	12	66
∑	78	428

Metode Konstan       

                                                                      

Bulan	Periode (t)	Demand (Dt)	dt'	e (dt - dt')	e2
1	1	10	36	-26	676
2	2	13	36	-23	529
3	3	18	36	-18	324
4	4	22	36	-14	196
5	5	27	36	-9	81
6	6	33	36	-3	9
7	7	35	36	-1	1
8	8	43	36	7	49
9	9	48	36	12	144
10	10	55	36	19	361
11	11	58	36	22	484
12	12	66	36	30	900
∑	78	428	432	-4	3754

               

                               

Metode Linier

Bulan	Periode (t)	Demand (Dt)	t2	t*dt	dt' ( 36 + 6t )	e (dt - dt')	e2
1	1	10	1	10	42.00	-32.00	1024.00
2	2	13	4	26	48.00	-35.00	1225.00
3	3	18	9	54	54.00	-36.00	1296.00
4	4	22	16	88	60.00	-38.00	1444.00
5	5	27	25	135	66.00	-39.00	1521.00
6	6	33	36	198	72.00	-39.00	1521.00
7	7	35	49	245	78.00	-43.00	1849.00
8	8	43	64	344	84.00	-41.00	1681.00
9	9	48	81	432	90.00	-42.00	1764.00
10	10	55	100	550	96.00	-41.00	1681.00
11	11	58	121	638	102.00	-44.00	1936.00
12	12	66	144	792	108.00	-42.00	1764.00
∑	78	428	650	3512	900	-472	18706

Metode Quadratic

Bulan	Periode (t)	Demand (Dt)	t2	t3	t4	t*dt	t2*dt	dt' (a+bt+ct2)	e (dt-dt')	e2
1	1	10	1	1	1	10	10	9.36	0.64	0.41
2	2	13	4	8	16	26	52	13.41	-0.41	0.17
3	3	18	9	27	81	54	162	17.68	0.32	0.10
4	4	22	16	64	256	88	352	22.17	-0.17	0.03
5	5	27	25	125	625	135	675	26.88	0.12	0.01
6	6	33	36	216	1296	198	1188	31.81	1.19	1.42
7	7	35	49	343	2401	245	1715	36.96	-1.96	3.84
8	8	43	64	512	4096	344	2752	42.33	0.67	0.45
9	9	48	81	729	6561	432	3888	47.92	0.08	0.01
10	10	55	100	1000	10000	550	5500	53.73	1.27	1.61
11	11	58	121	1331	14641	638	7018	59.76	-1.76	3.10
12	12	66	144	1728	20736	792	9504	66.01	-0.01	0.00
∑	78	428	650	6084	60710	3512	32816	428.02	-0.02	11.15

1.                                                  

Metode yang paling tepat untuk peramalan adalah metode quadratic. Hasil ramalan;

No.	Periode (t)	t2	dt’
1	13	169.00	72.48
2	14	196.00	79.17
3	15	225.00	86.08
4	16	256.00	93.21
5	17	289.00	100.56
6	18	324.00	108.13
7	19	361.00	115.92
8	20	400.00	123.93
9	21	441.00	132.16
10	22	484.00	140.61
11	23	529.00	149.28
12	24	576.00	158.17