Apparel Online Bangladesh Magazine May Issue 2019 | Page 52

MYTH BUSTER
MISUNDERSTANDINGS
ABOUT TNA CALENDAR
Time and Action Calendar or TNA is a technique for tracking and following up on the important
milestones in pre-production processes to ensure timely delivery within stipulated delivery date.
Despite claims of being practically in use by most buying and manufacturing organisations, the follow-
up of orders/styles during the pre-production processes are not foolproof and there are several myths
which need to be redressed.
I
n contract apparel
manufacturing scenario,
work is tracked through the
order fulfilment process (OFP)
by monitoring at specific order
points decided by critical path
reporting agreement by buyers
on manufacturers in developing
countries. However, different
terminologies were used by different
users like ‘time-and-action’, ‘critical
path’, ‘workflow’, merchandising
‘calendar time scale’. Many
apparel managers also use project
management concept such as Gantt
chart, to monitor time and manage
employees who work on product
development and production.
TNA should be same as
critical path
RIGHT
Garment pre-production (also
known as merchandising)
activities are characterised
by people-oriented functions.
Interdependent activities are
synchronised between succeeding
and preceding activities to make a
non-linear process network. The
longest chain of activities considering
task dependencies is called critical
path. TNA should have the same
activities as critical path derived
from PERT (Program Evaluation and
Review Technique) network or Gantt
chart.
Time is the most critical factor in
TNA or critical path
RIGHT
Even though most of the users are
aware of the term ‘critical path
method’ (or the CPM), surprisingly
few know the correct meaning
(definition as per operation
research) of ‘critical path’. The
interpretations of term ‘critical’ by
industry executives are varying.
While some feel ‘critical’ means
‘possibility of non-conformance is
higher’ as per previous experience,
others feel ‘critical’ means ‘most
time taking’; some even link ‘critical’
with ‘cost involving that activity’.
Everybody selects ‘critical’ activities
hypothetically based on intuition
or previous experience or buyer’s
milestones and no one actually
makes PERT network of activities
and then arrive at CPM.
Sequences of activities in garment
pre-production are linear
WRONG
It is a common practice to list
activities from order receipt to
delivery in linear sequence and
assigning time duration to each
activity by backward planning, which
is wrong as the activities are never
linear since there are lot of parallel
activities. Therefore, the sequence
of activities should be drawn either
52 Apparel Online Bangladesh | MAY 2019 | www.apparelresources.com
Gantt chart
as PERT network or Gantt chart
format.
Garment pre-
production
(also known as
merchandising)
activities are
characterised by
people-oriented
functions.
Interdependent
activities are
synchronised
between succeeding
and preceding
activities to make a
non-linear process
network.
How many and which all
activities should be there in
TNA depends on the buyer
WRONG
It was found that in majority of
the cases, the buyer specifies
target dates of key activities
and based on those target dates
the manufacturing organisation
creates their own TNA adding
buffer days (to ensure that buyer
target dates are not missed). It
was also a common practice to
have two TNAs: one with few
main important activities (also
called milestone activities) that