{"id":1300,"date":"2019-11-10T12:25:59","date_gmt":"2019-11-10T17:25:59","guid":{"rendered":"http:\/\/www.foxquestsystems.net\/foxblog\/?p=1300"},"modified":"2020-01-07T09:34:24","modified_gmt":"2020-01-07T14:34:24","slug":"start-to-start-relationships-with-no-lag-between-tasks","status":"publish","type":"post","link":"https:\/\/www.foxquestsystems.net\/foxblog\/2019\/11\/10\/start-to-start-relationships-with-no-lag-between-tasks\/","title":{"rendered":"Tasks With Start-To-Start Relationships And No Lag"},"content":{"rendered":"\n

The PDM (Precedence Diagram Method) method of defining relationships between activities is a powerful tool. Often, however, Schedulers, sometimes unknowingly, misuse the options available when defining relationships between activities. In the illustration below, under Method 1, Activity \u201cA\u201d is related to \u201cB\u201d using Finish-To-Start (FS) and \u201cB\u201d is related to \u201cC\u201d using Start-To-Start (SS) with Lag = 0. <\/p>\n\n\n\n

This may appear as a reasonable approach as often, the Activity Name description(s) may provide a false justification for this relationship. Unfortunately, the Forward and Backward pass doesn\u2019t care about your Activity Name description. Therefore, trying to justify the use of Method 1 by using a \u201creal world\u201d situation fails as an argument to promote its use.<\/p>\n\n\n\n

\"\"
The Forward and Backward Pass doesn’t care about your Activity Name description.<\/figcaption><\/figure><\/div>\n\n\n\n

By observation, since \u201cB\u201d has a\nshorter duration than \u201cC\u201d, \u201cB\u201d should have a higher Total Float (TF) value than\n\u201cC\u201d. However, when calculated, the TF for \u201cB\u201d = 0. Under Method 1, the SS\/Lag =\n0 relationship between \u201cB\u201d and \u201cC\u201d is causing the critical path to flow through\nthe only the Start of \u201cB\u201d resulting in an incorrect TF value for \u201cB\u201d. <\/p>\n\n\n\n

By representing \u201cB\u201d as a critical activity, the result could lead to a possible misallocation of resources. Furthermore, if the correct TF value \u201cB\u201d is later discovered, then this could cause a loss in trust in the schedule.<\/p>\n\n\n\n

The solution is to follow Method\n2, i.e. \u201cA\u201d is related to \u201cB\u201d using FS and \u201cA\u201d is related to \u201cC\u201d using FS. Not\nonly is this trap avoided but relationships between activities are more clearly\ndefined.<\/p>\n\n\n\n

Z\u00fcmmer checks this anomaly with Report #37 \u2013 \u201cTasks With Start-To-Start Relationships And No Lag\u201d reports all instances. In the illustration below, each Start-To-Start relationship with no lag is clearly and individually paired. In addition, the Activity Status of the predecessor and successor is listed along with each Original Duration, Total Float, type of Relationship and lag value between the two activities.<\/p>\n\n\n\n

\"\"<\/figure><\/div>\n\n\n\n

Copyright \u00a92019 FoxQuest Systems, Inc. – All Rights Reserved<\/p>\n","protected":false},"excerpt":{"rendered":"

The PDM (Precedence Diagram Method) method of defining relationships between activities is a powerful tool. Often, however, Schedulers, sometimes unknowingly, misuse the options available when defining relationships between activities. In the illustration below, under Method 1, Activity \u201cA\u201d is related to \u201cB\u201d using Finish-To-Start (FS) and \u201cB\u201d is related to \u201cC\u201d using Start-To-Start (SS) with … Continue reading “Tasks With Start-To-Start Relationships And No Lag”<\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":1301,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"nf_dc_page":"","om_disable_all_campaigns":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_feature_clip_id":0,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_post_was_ever_published":false},"categories":[2],"tags":[],"class_list":["post-1300","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-analysis"],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"https:\/\/i0.wp.com\/www.foxquestsystems.net\/foxblog\/wp-content\/uploads\/2019\/11\/Report-37-analysis-report-selection.jpg?fit=830%2C466&ssl=1","_links":{"self":[{"href":"https:\/\/www.foxquestsystems.net\/foxblog\/wp-json\/wp\/v2\/posts\/1300","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.foxquestsystems.net\/foxblog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.foxquestsystems.net\/foxblog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.foxquestsystems.net\/foxblog\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.foxquestsystems.net\/foxblog\/wp-json\/wp\/v2\/comments?post=1300"}],"version-history":[{"count":6,"href":"https:\/\/www.foxquestsystems.net\/foxblog\/wp-json\/wp\/v2\/posts\/1300\/revisions"}],"predecessor-version":[{"id":1447,"href":"https:\/\/www.foxquestsystems.net\/foxblog\/wp-json\/wp\/v2\/posts\/1300\/revisions\/1447"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.foxquestsystems.net\/foxblog\/wp-json\/wp\/v2\/media\/1301"}],"wp:attachment":[{"href":"https:\/\/www.foxquestsystems.net\/foxblog\/wp-json\/wp\/v2\/media?parent=1300"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.foxquestsystems.net\/foxblog\/wp-json\/wp\/v2\/categories?post=1300"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.foxquestsystems.net\/foxblog\/wp-json\/wp\/v2\/tags?post=1300"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}