🚗 Umugqa wokuhlanganisa izimoto Imodeli ephilayo

Isisekelo — imodeli engemuva kwezinombolo

Wonke ubudlelwano isilingisi esibusebenzisayo, nomthombo wabo. Izinto ezihlala zingashintshi ezimakwe njengokuthathelwa yizilinganiso zesibonelo.

I-OEE iphindaphinda ukutholakala, ukusebenza nesilinganiso sekhwalithi, kulinganiswe esikhaleni esincane; ilingana nesikhathi somjikelezo esifanele × amayunithi amahle ÷ isikhathi esihleliwe.

OEE = A × P × Q; A = (T_plan − T_stop)/T_plan, P = CT_ideal · N_bn / (T_plan − T_stop), Q = N_first-pass / N_out; OEE = CT_ideal · N_good / T_plan when N_bn = N_out[1][2]Umkhiqizo ulingana nesikhathi somjikelezo esifanele × amayunithi alungile ÷ isikhathi esihleliwe kuphela uma okuphumayo kwesikhawu esinciphile kulingana nokuphuma komugqa; amayunithi asese phakathi kwesiteshi 3 nokuphela komugqa enza umehluko omncane.

Isiteshi sidlulisela iyunithi yaso kuphela uma ibhafa elilandelayo linendawo (ngaphandle kwalokho sivinjiwe) futhi siqala kuphela uma ibhafa langaphambilini linayunithi (ngaphandle kwalokho sinendlala).

station i: cycle = c_i / v; moves on iff buffer_i < K (else blocked); starts iff buffer_{i−1} > 0 (else starved)[3][4]

Umugqa awukwazi ukusebenza ngokushesha kunesiteshi sawo esiyisihlwathi; isikhathi se-takt yisikhathi esitholakalayo esihlukaniswe isidingo.

r_line ≤ r_b = v / max_i c_i; takt = available time / demand = 60 / plan [min/unit][5][7]

Imfutho yejubane: ukulahlekelwa okuqhutshwa yijubane kukhula ngaphandle komkhawulo njengoba umugqa usondela emkhawulweni wezinsiza nabasebenzi (105 % wejubane elinqunyiwe).

σ_n(v) = ((1.05 − 0.85) / (1.05 − v))^n (σ = 1 at 85 %; σ_1: 2× at 95 %, 4× at 100 %; σ_2: 4× at 95 %, 16× at 100 %)Okucatshangwayo: izikhathi zomjikelezo, izikhathi zokuhluleka nokulungisa, amazinga amaphutha nokumiswa kwamanga, umthetho wemfutho wejubane nobukhulu bamaqembu yizinani zesibonelo, hhayi idatha evela efektri yangempela.

Iziteshi zehluleka kuphela lapho zisebenza, kaningi lapho umugqa usebenza usondele emkhawulweni wawo; isikhathi sokulungisa siyafushaniswa lapho kujoyina uchwepheshe wesibili.

P(fail in Δt) = 1 − exp(−λ_i · t_work), λ_i = σ_1(v) / MTBF_i; repair work ~ Erlang-3(mean MTTR_i), done at rate 1 + 0.6·(n−1), n ≤ 2[4][1]Okucatshangwayo: izikhathi zomjikelezo, izikhathi zokuhluleka nokulungisa, amazinga amaphutha nokumiswa kwamanga, umthetho wemfutho wejubane nobukhulu bamaqembu yizinani zesibonelo, hhayi idatha evela efektri yangempela.

Amaphutha anyuka kakhulu ngejubane kunokwehluleka. Nge-andon amaphutha amaningi athathwa alungiswe esiteshini, ngenani lokumiswa okufushane (okunye kungama-alamu amanga); uma kungenjalo ukuhlolwa ekupheleni komugqa kubamba amanye futhi asele abalekela.

p_i = p0_i · σ_2(v) (+0.12 excursion at S4); andon: detect 90 %, stop 1.5 min, fix; false stops 0.3 % · σ_2(v) per unit and station; end-of-line test catches 70 %[7][1]Okucatshangwayo: izikhathi zomjikelezo, izikhathi zokuhluleka nokulungisa, amazinga amaphutha nokumiswa kwamanga, umthetho wemfutho wejubane nobukhulu bamaqembu yizinani zesibonelo, hhayi idatha evela efektri yangempela.

Umthetho kaLittle: isikhathi esiphakathi emugqeni silingana nomsebenzi osenqubekweni owahlukaniswe ngokuphuma.

lead time W = WIP / throughput (L = λW)[6][5]

Ezinye izinto ezingashintshi zokusebenza ezisetshenziswa imodeli.

cycle c = 0.62/0.64/0.90/0.75/0.72 min at rated speed (S3 = bottleneck) · MTBF 120/100/200/110/150 min of work, MTTR 4/4/3/4/3 min at 85 % speed · S2 part replacement 40 technician-min · p0 = 0.15/0.15/0.2/0.2/0.05 % per unit · excursion contained after 3 andon pulls or 15 units caught at test · rework 4 min/unit, team of 3 for 1 h per call · 40 line operators · moving averages over 30 minOkucatshangwayo: izikhathi zomjikelezo, izikhathi zokuhluleka nokulungisa, amazinga amaphutha nokumiswa kwamanga, umthetho wemfutho wejubane nobukhulu bamaqembu yizinani zesibonelo, hhayi idatha evela efektri yangempela.

Ukungahleliwe: i-generator ye-mulberry32 enembewu; ukusabalalisa okusetshenzisiwe — uniform, exponential (inverse CDF), normal (Box–Muller), Poisson (Knuth). Imbewu iyabonisa futhi ingabelwana.

Imithombo

1. S. Nakajima — Introduction to TPM: Total Productive Maintenance (OEE = availability × performance × quality; six big losses) — Productivity Press, 1988
2. ISO 22400-2:2014 — Automation systems and integration — KPIs for manufacturing operations management — Part 2: Definitions and descriptions (availability, effectiveness, quality ratio, OEE index) — ISO, 2014
3. J. A. Buzacott, J. G. Shanthikumar — Stochastic Models of Manufacturing Systems (flow lines with finite buffers, blocking, starvation) — Prentice Hall, 1993
4. Y. Dallery, S. B. Gershwin — Manufacturing flow line systems: a review of models and analytical results (operation-dependent failures, blocking after service) — Queueing Systems 12, 1992
5. W. J. Hopp, M. L. Spearman — Factory Physics, 3rd ed. (bottleneck rate, variability buffering, Little’s law) — Waveland Press, 2011
6. J. D. C. Little — A Proof for the Queuing Formula L = λW — Operations Research 9(3), 1961
7. T. Ohno — Toyota Production System: Beyond Large-Scale Production (jidoka, stopping the line on abnormalities, takt) — Productivity Press, 1988